Electron spin resonance measurement device

Abstract

To provide an ESR measurement device that detects from a sample a phenomenon involving electron spins in response to voltage application or light irradiation when using a device, as the sample for ESR measurement, that responds to voltage application or light irradiation.SOLUTION: A cavity 14 is placed within a static magnetic field generated by an electromagnet 16. A sample 12 responsive to the supply of voltage or light is housed in the cavity 14. The sample 12 is repeatedly irradiated with microwaves, and voltage is repeatedly applied to the sample 12 or light is repeatedly irradiated to the sample 12 in synchronization with the irradiation of the microwaves. A repetition frequency of the supply of voltage or light is a frequency that is higher than or equal to a repetition frequency of the microwave irradiation. A signal obtained from the sample 12 in response to the supply of voltage or light is measured.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electron spin resonance (hereinafter also referred to as "ESR") measuring device. [Background technology]

[0002] In general, in electron spin resonance spectroscopy, a sample is placed in a cavity placed in a static magnetic field. In the cavity, electromagnetic energy is applied to the electron spins in the sample. The Zeeman energy (gμ B B o ) coincides, electromagnetic energy is absorbed in the sample, and the phenomenon is observed as electron spin resonance. Here, h is the Planck constant, ν is the frequency of the electromagnetic wave, g is a proportionality constant called the g value, and μ B is the Bohr magneton.

[0003] In an ESR measurement device, when the direction of the static magnetic field is taken as the z-axis, the electron spins in the sample have magnetization (Mz) parallel to the z-axis direction. In this state, microwaves are supplied and the static magnetic field is swept (specifically, the strength of the static magnetic field is changed). In this process, when the resonance condition is satisfied, an oscillating magnetization (transverse magnetization) component (My) in the y-axis direction is generated. A typical "ESR spectrum" observed in an ESR measurement device is a spectrum formed by plotting the change in the oscillating magnetization component (My) against the change in the strength of the static magnetic field.

[0004] Patent Document 1 describes an electrically detected magnetic resonance (EDMR) measurement method and an optically detected magnetic resonance (ODMR) measurement method.

[0005] Patent Document 2 describes a method in which a sample is irradiated with microwave pulses and light at the same time to detect a signal.

[0006] Time-resolved ESR measurement is also known. Time-resolved ESR measurement is a method in which, when a compound (radical species) having an unpaired electron exists as a product or intermediate reaction state, a certain reaction initiation event is used as a trigger, and sequential ESR signals or electron paramagnetic resonance (EPR) signals reflecting the electronic state, local molecular structure, and reaction rate of the radical species are recorded as spectra or absorption / emission amounts, and evaluated, as shown in the following formula (1) or (2). In the following, EPR is included in the concept of ESR.

number

number

[0007] The methods for measuring time-resolved ESR spectra and signals are broadly divided into two types, depending on the time resolution step size (i.e., time resolution).

[0008] Hereinafter, the conventional time-resolved ESR measurement method A will be described. In the chemical reaction as shown in the above formula (1), when the lifetime of the radical species generated is relatively long (for example, milliseconds or more), the time-resolved ESR measurement method A is applied. In the time-resolved ESR measurement method A, a specific trigger phenomenon is, for example, a phenomenon that occurs at the moment when substance A and substance B are mixed, or a phenomenon that occurs at the moment when the temperature of a system in which substance A and substance B are mixed is controlled to a certain temperature.

[0009] Figure 15 shows the configuration of an ESR measurement device that realizes the time-resolved ESR measurement method A. Figure 16 shows the procedure of this time-resolved ESR measurement method A and the measurement results.

[0010] In time-resolved ESR measurement method A, an electrical trigger is generated (see symbol 540 in Figure 16(a)) when the temperature of sample 500 is controlled to a certain temperature or when sample A and sample B (usually both are liquid) are mixed into a measurement sample tube, and the ESR spectrum is recorded at a certain time interval from that point on.

[0011] Specifically, a cavity 502 is placed between the poles of an electromagnet 504 that generates a sweepable static magnetic field, and a sample 500 is placed in the cavity 502. A modulation coil 506 capable of modulating the value of the static magnetic field is placed inside or outside the cavity 502, and a magnetic field modulation signal is applied to the modulation coil 506 by a modulation signal generator 508. At the same time, a microwave with a frequency ν is output from a microwave oscillator 510. The microwave is adjusted to an appropriate power by an attenuator 512, and then introduced into the cavity 502 via a circulator 514. At this time, the cavity 502 and the waveguide are impedance-matched, and there is no reflected power. When the current value of the electromagnet 504 is changed (for example, increased) so that the value of the magnetic field and the frequency of the microwave satisfy the condition shown in the following formula (3), ESR absorption occurs. hν=gμ B B. (3) Here, μ B is the Bohr magneton and B is the magnitude of the magnetic field.

[0012] When this resonance condition is established, the impedance matching between the cavity 502 and the waveguide is broken, causing reflected power, which is converted into a DC current (or a DC voltage) by a phase detector 516 via a circulator 514. The phase detector 516 is connected to a microwave oscillator 510 via a phase shifter 518. The converted DC signal is modulated at a conversion magnetic field frequency (generally 100 kHz), amplified by a preamplifier 520, and then detected by a lock-in amplifier 522 (composed of a phase detector 524 and a preamplifier 526), ​​and converted into a digital signal by an AD converter 528. The digital signal is processed as a spectrum by a PC (personal computer) 530.

[0013] Time-resolved ESR measurement method A is performed according to the procedure shown in Fig. 16(a). As described above, the trigger signal 540, which is the starting point of the measurement, is obtained as some kind of electronic signal the moment the temperature of the sample 500 is determined or the moment the reaction solution is mixed. After a predetermined delay time from the moment this trigger signal 540 is obtained, the magnetic field sweep, i.e., the ESR spectrum measurement, is started.

[0014] If the first measurement is represented as Sweep #1, then after the magnetic field sweep ends, the second measurement, Sweep #2, starts after a certain interval. After the magnetic field sweep ends, the third measurement, Sweep #3, starts after a certain interval. This series of continuous measurements is performed N times, as specified in advance.

[0015] There are two main ways to output the results. Figure 16(b) shows one way, and Figure 16(c) shows another way.

[0016] The method shown in Figure 16(b) is a method of displaying ESR spectra arranged in a time series of reaction times, while the method shown in Figure 16(c) is a method of plotting only the signal intensity at a certain peak position of the spectrum in a time series of reaction times.

[0017] The method shown in Fig. 16(b) is effective for investigating the electronic state from the time series analysis of the spectral line shape, while the method shown in Fig. 16(c) is effective for analyzing the reaction rate.

[0018] Time-resolved ESR measurement method A is used to track chemical reactions with relatively slow reaction rates. The time resolution must be sufficiently longer than the period of the modulated magnetic field. For example, a magnetic field modulation of 100 kHz results in a period of 10 μs, and any time significantly longer than this results in a time resolution of milliseconds or more. To capture a shorter time resolution, particularly a short-lived reaction intermediate such as that shown in formula (2) above, time-resolved ESR measurement method B, described below, is required.

[0019] Below, we will explain time-resolved ESR measurement method B. Figure 17 shows the configuration of an ESR measurement device that realizes time-resolved ESR measurement method B. Figure 18 shows the procedure for this time-resolved ESR measurement method B and the measurement results. Note that when people say time-resolved ESR, they often mean time-resolved ESR measurement method B or the device for it.

[0020] The lifetime of reaction intermediates as shown in the above formula (2) is very short, so a method for acquiring signals quickly and with high sensitivity is required. When attempting to capture short-lived reaction intermediates using time-resolved ESR measurement, time-resolved ESR measurement method B has been adopted for the purpose of detecting reaction intermediates produced by photochemical reactions.

[0021] The time-resolved ESR measurement method B has the following features (1) to (3). (1) Since the magnetic field modulation method is not used, no modulation coil is used. (2) The trigger that starts signal acquisition is a switch signal that accompanies pulsed laser irradiation. (3) The ESR signal is amplified by a faster (broadband) preamplifier and then directly input into a device such as an oscilloscope, continuous averager, or boxcar integrator, rather than into a lock-in amplifier.

[0022] In time-resolved ESR measurement method B, a cavity 602 in which a sample 600 is placed is placed between the poles of an electromagnet 604 under a static magnetic field generated by the electromagnet 604. Microwaves of frequency ν are output by an oscillator 606, adjusted to an appropriate power by an attenuator 608, and then introduced into the cavity 602 via a circulator 610.

[0023] The waveguide of the cavity 602 is impedance-matched and maintained in a state of no reflected power. In a normal ESR device, the current of the electromagnet 604 is continuously swept and a signal is obtained by lock-in detection at the point where it matches the above formula (3). However, in the time-resolved ESR measurement method B, the signal is obtained by a stepwise sequence operation as shown in Fig. 18(a).

[0024] First, the static magnetic field is set to a certain value M#1, and then the light oscillated by the laser light source 612 is shaped into a pulse by the switch 614 and irradiated onto the sample 600. The switch signal at this time is used as a trigger signal to capture the output of the wideband preamplifier 620 into a signal capture device 622 (high-speed digitizer (oscilloscope, continuous averager) or boxcar integrator). The trigger is generated by a trigger generator 626. At this time, in order to increase the signal-to-noise ratio of the signal, it is normal to perform a specified number of calculation processes. The wideband preamplifier 620 is connected to the circulator 610 via a phase detector 616, and the phase detector 616 is connected to the oscillator 606 via a phase shifter 618.

[0025] When the integration process is completed, the captured waveform data or signal intensity data is stored in the PC 624 as the value of the magnetic field M#1.

[0026] Next, the magnetic field value is changed to magnetic field M#2, and the laser irradiation and signal integration process are performed in the same way. Each time the magnetic field value is changed stepwise in this way, the ESR signal at that magnetic field value (i.e., the transient response signal due to laser irradiation) is recorded, and finally, a spectrum with the magnetic field value on the horizontal axis and the signal intensity on the vertical axis is generated by PC624.

[0027] When the signal acquisition device 622 is an acquisition device that employs a digitizer type waveform recording method, the time change of the ESR spectrum depending on the time from the laser irradiation time can be obtained as shown in FIG. 18(b).

[0028] Figure 18(c) shows the result of plotting the ESR signal intensity at a certain time for a certain magnetic field value, which can be used to analyze, for example, reaction rates.

[0029] The boxcar integrator integrates only the signal strength of a specific time region of the transient response signal. Therefore, when trying to obtain the results shown in Figures 18(b) and 18(c), the same results can be obtained by repeating the experiment by changing the delay time from the laser irradiation time (i.e., the specified time region of the boxcar integrator) to a certain time interval. [Prior art documents] [Patent documents]

[0030] [Patent Document 1] JP 2020-34434 A [Patent Document 2] JP 2016-75665 A Summary of the Invention [Problem to be solved by the invention]

[0031] The above-mentioned conventional time-resolved ESR measurement method has the following problems.

[0032] The time-dependent transient response of devices that function using voltage or light as driving events (e.g., rectifier diodes and light-emitting diodes) is dominated by carrier electrons that are not related to ESR, parasitic stray capacitance in the circuit, and displacement currents resulting from the capacitance of the device itself. Therefore, when time-resolved ESR measurements are performed on such devices, it is not possible to selectively observe the behavior of the initial electron spin. For example, in a silicon rectifier diode, when electron spin is involved in the recombination current, the contribution of electron spin to the total carriers is 10 -6 From 10 -4 It's a very small proportion of that.

[0033] Even if one attempts to detect such a phenomenon using, for example, a PLDMR (Photoluminescence detected magnetic resonance) measurement method using an apparatus that realizes the above-mentioned time-resolved ESR measurement method B, it is not possible to selectively extract only the components originating from the electron spin from the transient response of the light emission, and therefore it is not possible to determine whether the obtained photoluminescence signal is originating from the electron spin or not.

[0034] Furthermore, when it comes to measuring the transient current response of a voltage-driven diode or the transient light emission response of a voltage-driven light-emitting diode, there is no means for selectively extracting transient recombination-related phenomena that depend on electron spin using a configuration similar to the time-resolved ESR measurement method B described above.

[0035] If the current response or optical response is related to electron spin in a steady state of voltage application or light irradiation, rather than a transient change in the electronic state at the moment when a voltage is applied to a device or when light is irradiated, it can be detected by a method such as the so-called CW-EDMR (Continuous Wave Electrically Detected Magnetic Resonance) measurement method or the CW-ODMR (Continuous Wave Optically Detected Magnetic Resonance) measurement method. However, these measurement methods are only for steady-state measurements.

[0036] An object of the present invention is to detect a phenomenon involving electron spin from the sample in response to the application of a voltage or the irradiation of light when a device responsive to the application of a voltage or the irradiation of light is used as a sample for ESR measurement in an ESR measurement apparatus. [Means for solving the problem]

[0037] One aspect of the present invention includes a static magnetic field generator that generates a static magnetic field, a cavity that is placed in the static magnetic field, contains a sample that responds to the supply of voltage or light, and generates electron spin resonance in the sample when microwaves are supplied, microwave irradiation means that repeatedly irradiates the sample with microwaves, supply means that drives the sample by repeatedly supplying voltage or light to the sample in synchronization with the microwave irradiation, and measurement means that measures a signal reflecting the electron spin resonance generated in the sample, wherein the repetition frequency of the supply of voltage or light is equal to or greater than the repetition frequency of the microwave irradiation. Upper circumference The electron spin resonance measurement apparatus is characterized in that the wave number is a wave number.

[0038] The supplying means may repeatedly supply a rectangular voltage pulse or light pulse to the sample.

[0039] The voltage pulse or light pulse may be a rectangular wave with a duty ratio of 50%, and the microwave irradiation means may repeatedly irradiate the sample with a microwave pulse having a pulse width with a duty ratio other than 50%.

[0040] The repetition frequency of the supply of the voltage pulse or light pulse and the repetition frequency of the irradiation of the microwave pulse may be the same frequency, and the measuring means may use a bandpass filter having a center frequency that is twice the repetition frequency to extract a specific frequency component from the signal obtained from the sample in response to the supply of the voltage pulse or light pulse, and measure the specific frequency component as a signal due to electron spin resonance.

[0041] The repetition frequency of the supply of the voltage pulse or light pulse is twice the repetition frequency of the irradiation of the microwave pulse, and the measuring means may use a low-pass filter to extract a specific frequency component lower than the repetition frequency of the irradiation of the microwave pulse from the signal obtained from the sample in response to the supply of the voltage pulse or light pulse, and measure the specific frequency component as a signal caused by electron spin resonance.

[0042] The microwave irradiation means may irradiate the sample with a microwave pulse by delaying the timing of irradiating the sample with a microwave pulse based on the timing at which a voltage pulse or a light pulse is supplied to the sample, and may change the timing of irradiating the microwave pulse for each measurement.

[0043] The supplying means may supply a voltage pulse or light pulse to the sample by delaying the timing of supplying a voltage pulse or light pulse to the sample based on the timing at which a microwave pulse is supplied to the sample, and may change the timing of supplying the voltage pulse or light pulse for each measurement.

[0044] The measuring means may further calculate an integrated value of a signal obtained from the sample in response to the supply of a voltage pulse or a light pulse. Effect of the Invention

[0045] According to the present invention, in an ESR measurement apparatus, when a device that responds to the application of a voltage or irradiation with light is used as a sample to be subjected to ESR measurement, a phenomenon involving electron spin can be detected from the sample in response to the application of a voltage or irradiation with light. [Brief description of the drawings]

[0046] [Figure 1] 1 is a block diagram showing the configuration of an ESR measurement device according to a first embodiment. FIG. [Diagram 2] FIG. 2 is a diagram showing each signal according to the first embodiment. [Diagram 3] FIG. 4 is a diagram showing each frequency component of a response signal generated when a resonance condition is not satisfied in the first embodiment. [Figure 4] FIG. 4 is a diagram illustrating each frequency component of a response signal generated when a resonance condition is satisfied in the first embodiment. [Diagram 5] FIG. 4 is a diagram illustrating frequency components of a signal output from a bandpass filter when a resonance condition is satisfied in the first embodiment. [Figure 6]FIG. 2 is a diagram showing measurement methods A and B according to the first embodiment. [Figure 7] FIG. 4 is a diagram showing a timing chart of measurement by a boxcar integrator in the first embodiment. [Figure 8] FIG. 11 is a block diagram showing the configuration of an ESR measurement apparatus according to a second embodiment. [Figure 9] FIG. 11 is a diagram showing each signal according to the second embodiment. [Figure 10] FIG. 11 is a diagram showing each frequency component of a response signal generated when a resonance condition is not satisfied in the second embodiment. [Figure 11] FIG. 11 is a diagram illustrating each frequency component of a response signal generated when a resonance condition is satisfied in the second embodiment. [Figure 12] FIG. 11 is a diagram illustrating frequency components of a signal output from a low-pass filter when a resonance condition is satisfied in the second embodiment. [Figure 13] FIG. 11 is a diagram showing measurement methods A and B according to the second embodiment. [Figure 14] FIG. 1 shows the results of measurement by a time-resolved ELDMR method. [Figure 15] FIG. 1 is a block diagram showing the configuration of an ESR measuring device according to a conventional technique. [Figure 16] FIG. 1 is a diagram showing a time-resolved ESR measurement method according to the prior art. [Figure 17] FIG. 1 is a block diagram showing the configuration of an ESR measuring device according to a conventional technique. [Figure 18] FIG. 1 is a diagram showing a time-resolved ESR measurement method according to the prior art. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] The ESR measuring device according to the first and second embodiments will be described below. The ESR measuring device according to the first and second embodiments is a device that realizes a time-resolved ESR measuring method. Hereinafter, the method according to the first embodiment will be referred to as the "BPF (Band Pass Filter)-2ω method," and the method according to the second embodiment will be referred to as the "LPF (Low Pass Filter)-ω method." In the BPF-2ω method and the LPF-ω method, a time-resolved signal can be obtained by either measurement method A or measurement method B, which will be described later.

[0048] The samples used for measuring time-resolved ESR signals are semiconductor device A, which generates a recombination current when driven by electric current or voltage, semiconductor device B, which is accompanied by a light emission phenomenon in a similar recombination process, semiconductor device C, which generates carriers by exciting the device with light of a certain wavelength and generates a recombination current, and semiconductor device D, which generates light of a wavelength different from the excitation light due to the photoluminescence phenomenon when the carriers recombine.

[0049] A magnetic resonance method for detecting the electrical behavior of a semiconductor device is called an EDMR (Electrically Detected Magnetic Resonance) method, and a magnetic resonance method for detecting the optical behavior of a semiconductor device is called an ODMR (Optically Detected Magnetic Resonance) method.

[0050] As will be explained below, these techniques are further subdivided into different names depending on the physical phenomenon they detect. The magnetic resonance method for detecting the recombination current in semiconductor device A is called the Electrically Detected Magnetic Resonance (EDMR) method. The magnetic resonance method for detecting the light emission from semiconductor device B is called the ELDMR (Electro Luminescence Detected Magnetic Resonance) method. The magnetic resonance method for detecting the recombination current in semiconductor device C is called the Photo-Current Detected Magnetic Resonance (PCDMR) method. The magnetic resonance method for detecting the light emission from a semiconductor device D is called the Photo Luminescence Detected Magnetic Resonance (PLDMR) method.

[0051] In the following, the first embodiment will be described first, and then the second embodiment will be described.

[0052] First Embodiment An ESR measuring apparatus according to the first embodiment will be described with reference to Fig. 1. Fig. 1 shows an example of the configuration of an ESR measuring apparatus 10 according to the first embodiment.

[0053] The configuration and operation of the ESR measurement apparatus 10 for implementing the time-resolved EDMR method, the time-resolved ELDMR method, the time-resolved PCDMR method, and the time-resolved PLDMR method will be described below.

[0054] (Time-resolved EDMR) The configuration and operation of the ESR measurement apparatus 10 for implementing the time-resolved EDMR method will be described.

[0055] The sample 12 to be measured is placed in a cavity 14, which is a microwave resonator. The sample 12 is a device such as the above-mentioned semiconductor devices A, B, C, and D. As described below, a voltage pulse or an optical pulse is supplied to the sample 12 depending on the type of the sample 12, thereby driving the sample 12. In addition, a microwave pulse is irradiated onto the sample 12. The cavity 14 is placed between the magnetic poles of two electromagnets 16 capable of sweeping a magnetic field, and thus the cavity 14 is placed within a static magnetic field generated by the electromagnets 16. The two electromagnets 16 form a static magnetic field generator.

[0056] The arbitrary waveform generator 18 is connected to the sample 12, which is a device, and functions as a drive power source for the sample 12. The arbitrary waveform generator 18 is connected to a multi-channel arbitrary waveform generator 20 that repeatedly generates a master clock according to a frequency ω that is a fundamental frequency. In other words, the repetition frequency of the master clock is frequency ω. The arbitrary waveform generator 18 repeatedly generates a bias voltage synchronized with the master clock and applies it to the sample 12, thereby driving the sample 12. The bias voltage generated by the arbitrary waveform generator 18 is, for example, a rectangular pulse voltage. The repetition frequency of the application of the bias voltage to the sample 12 is frequency ω. The rectangular pulse voltage is a pulse in which 50% of one period is in the on state (i.e., Duty 50% (duty ratio 50%)).

[0057] The arbitrary waveform generator 22 is connected to the multi-channel arbitrary waveform generator 20 and is synchronized by a master clock repeatedly generated by the multi-channel arbitrary waveform generator 20. After a certain delay time with respect to the master clock, the arbitrary waveform generator 22 repeatedly outputs a logic signal having an arbitrary pulse width to the switch 24 according to the frequency ω.

[0058] The microwave oscillator 26 operates at a frequency of v m The microwave oscillator 26 generates a microwave having a frequency of v m The microwave is power-adjusted by attenuator 27 and then sent to switch 24 .

[0059] The switch 24 receives the logic signal generated by the arbitrary waveform generator 22 and repeatedly outputs a microwave pulse signal shaped into a pulse shape. The repetition frequency is ω. The switching device realizing the switch 24 may be not only an ON / OFF control type SPST (single pole, single throw) or SPDT (single pole, double throw) switch, but also a device having a switch function that enables pulse shaping of any shape, such as a DBM (Double Balanced Mixer).

[0060] The microwave pulse output from the switch 24 is amplified in intensity by the power amplifier 28 and introduced into the cavity 14 via the circulator 30. A dummy load 31 is connected to the circulator 30. The microwave pulse is a signal having a pulse width with a duty ratio other than 50%.

[0061] Fig. 2 shows each signal according to the first embodiment. The horizontal axis in Fig. 2 represents time.

[0062] 2(a) shows the on / off timing of the master clock generated by the multi-channel arbitrary waveform generator 20. The repetition frequency of the master clock is ω.

[0063] 2(b) shows the timing at which the arbitrary waveform generator 18 applies a bias voltage pulse to the sample 12. The repetition frequency of the bias voltage pulse is frequency ω, and the bias voltage pulse is repeatedly applied to the sample 12 in accordance with frequency ω.

[0064] 2(c) shows the timing of irradiating the microwave pulse to the sample 12. The repetition frequency of the microwave pulse is frequency ω, and the microwave pulse is irradiated repeatedly to the sample 12 in accordance with frequency ω.

[0065] 2(d) and 2(e) show waveforms of signals emitted from the sample 12 in response to the irradiation of a microwave pulse. The signals emitted from the sample 12 are either current, voltage or emission intensity depending on the type of the sample 12 (i.e., device).

[0066] The bias voltage pulse is synchronized with the master clock and is, for example, a rectangular pulse with a duty of 50%. The microwave pulse is delayed by a certain time t d After that, the sample 12 is irradiated.

[0067] When the microwave pulse is off (i.e., the microwave pulse is not irradiated to the sample 12) or when the microwave frequency ν m and the static magnetic field B are the resonance conditions (hν m =gμ B When the response signal from the sample 12 does not match B), as shown in FIG. 2(d), the response signal from the sample 12 becomes a signal having a similar waveform to the bias voltage pulse (for example, a rectangular pulse signal with a duty of 50%).

[0068] On the other hand, the microwave pulse is on (i.e., the microwave pulse is irradiated to the sample 12) and the microwave frequency v m and the static magnetic field B are the resonance conditions (hν m =gμ B When the condition B) is met, the response signal from the sample 12 becomes a waveform signal that includes a minute fluctuation component 100 synchronized with the microwave pulse in addition to a signal having a similar waveform to the bias voltage pulse, as shown in FIG. 2(e).

[0069] When the EDMR method is performed, a response signal output from the sample 12 is input to the preamplifier 32 and amplified by the preamplifier 32.

[0070] When the current of the electromagnet 16 is controlled to sweep the magnetic field while maintaining the generation of the response signal, the resonance condition (hν m =gμ B If condition B) is not met, the response signal shown in Fig. 2(d) is output from the preamplifier 32. This response signal is a square wave with a duty of 50%, similar to the bias voltage pulse signal, so that not only the fundamental frequency ω component but also frequency components that are odd multiples of the fundamental frequency ω, such as 3ω and 5ω, are generated as so-called harmonics (see Transistor Technology, February 2001 issue, pp. 293-299). Fig. 3 shows the frequency components of the response signal that are generated when the resonance condition is not met.

[0071] On the other hand, when the magnetic field B is at the resonance condition (hν m =gμ BWhen condition B) is satisfied, the response signal shown in FIG. 2(e) is output from the preamplifier 32. This response signal contains distorted components (i.e., minute fluctuation components 100) caused by ESR resonance, so the shape of the waveform of this response signal is slightly deformed from the shape of the waveform of the response signal when the resonance condition is not satisfied. Therefore, not only harmonic components that are odd multiples of the fundamental frequency ω, but also frequency components that are even multiples of the fundamental frequency ω, such as 2ω and 4ω, are generated. FIG. 4 shows each frequency component of the response signal generated when the resonance condition is satisfied.

[0072] In the first embodiment, a bandpass filter 34 is connected to the preamplifier 32, and the response signal amplified by the preamplifier 32 is output to the bandpass filter 34. The bandpass filter 34 is a bandpass filter with a center frequency of 2ω. The response signal output from the preamplifier 32 passes through the bandpass filter 34.

[0073] A lock-in amplifier 36 is connected to the band-pass filter 34 , and the signal output from the band-pass filter 34 is input to the lock-in amplifier 36 .

[0074] When the response signal is a non-resonant response signal (i.e., a response signal when the resonance condition is not satisfied), when the response signal passes through the band-pass filter 34, no signal is output from the band-pass filter 34. In other words, no signal is output from the band-pass filter 34, and no signal is input to the lock-in amplifier 36.

[0075] When the response signal is a response signal at the time of resonance (i.e., a response signal when the resonance condition is satisfied), when the response signal passes through the bandpass filter 34, the signal output from the bandpass filter 34 becomes a signal containing only the 2ω component, as shown in Fig. 5. The 2ω component signal output from the bandpass filter 34 is input to the lock-in amplifier 36.

[0076] The lock-in amplifier 36 receives a reference signal repeatedly sent from the multi-channel arbitrary waveform generator 20 at a frequency of 2ω, and selectively detects with high sensitivity only the components due to ESR from the response signal of the sample 12 to the bias voltage.

[0077] The magnetic field B is swept, and the value of the 2ω component detected by the lock-in amplifier 36 for the swept magnetic field B value is converted to a digital signal by an ADC (Analog to Digital Converter) 38 and then processed by a PC 40. This generates an EDMR spectrum.

[0078] The band-pass filter 34 and the lock-in amplifier 36 constitute an example of a measuring means.

[0079] 6 shows a measurement method A and a measurement method B for obtaining a time-resolved EDMR spectrum or a time-resolved EDMR signal by the ESR measurement apparatus 10 according to the first embodiment. By executing either the measurement method A or the measurement method B, a time-resolved EDMR spectrum or a time-resolved EDMR signal can be obtained.

[0080] Fig. 6(a) shows the on / off timing of the master clock generated by the multi-channel arbitrary waveform generator 20. Fig. 6(b) and Fig. 6(d) show the timing when the arbitrary waveform generator 18 applies a bias voltage pulse to the sample 12. Fig. 6(c) and Fig. 6(e) show the timing when a microwave pulse is irradiated to the sample 12. The horizontal axis in Fig. 6 represents time.

[0081] Figures 6(b) and 6(c) are diagrams illustrating measurement method A. Figures 6(d) and 6(e) are diagrams illustrating measurement method B. First, measurement method A will be described, and then measurement method B will be described.

[0082] (Measurement Method A) In measurement method A, the phase difference of the bias voltage pulse with respect to the master clock (or the delay time of the bias voltage pulse with respect to the master clock) is fixed. On the other hand, the delay time t d is changed for each spectrum measurement. d The microwave pulse before the delay time t is changed is shown by a solid line (see reference numeral 110). d The microwave pulses whose amplitudes have been changed are shown by dashed lines (see reference numerals 112 and 114).

[0083] Delay time t d By changing the delay time t for each spectrum measurement, the spectrum obtained becomes a time-resolved spectrum group corresponding to the relative time change with respect to the bias voltage pulse. d By arranging the corresponding spectra for t, we obtain a time-resolved EDMR spectrum data set as shown in Fig. 18(b). Without magnetic field sweep, we fix the magnetic field B at the resonance field and measure only the signal intensity with a delay time t d Plotting this versus gives the kinetic data shown in Figure 18(c).

[0084] (Measurement method B) In measurement method B, the delay time of the microwave pulse with respect to the master clock is fixed. Meanwhile, the phase difference Δφ of the bias voltage pulse with respect to the master clock is changed for each spectrum measurement. In Fig. 6(d), the bias voltage pulse before the phase difference Δφ is changed is shown by a solid line (see reference numeral 120), and each bias voltage pulse with the phase difference Δφ changed is shown by a dashed line (see reference numerals 122 and 124).

[0085] By changing the phase difference Δφ for each spectrum measurement, the obtained spectrum becomes a time-resolved spectrum group corresponding to the relative time change with respect to the bias voltage pulse, as in measurement method A. By arranging the corresponding spectra with respect to the phase difference Δφ, a time-resolved ESMR spectrum data set as shown in Figure 18(b) is obtained. Without magnetic field sweeping, with magnetic field B fixed to the resonant magnetic field, only the signal intensity is measured with a delay time t dPlotting this versus gives the kinetic data shown in Figure 18(c).

[0086] The ESR measurement apparatus 10 also includes a boxcar integrator 42 connected to the preamplifier 32. The signal output from the preamplifier 32 is input to the boxcar integrator 42. The boxcar integrator 42 extracts a current level (I) obtained when the microwave pulse is irradiated to the sample 12 from a current signal obtained from the sample 12 in response to application of a bias voltage pulse to the sample 12. An ADC 44 is connected to the boxcar integrator 42, and the current level (I) extracted by the boxcar integrator 42 is converted into a digital signal by the ADC 44 and output to the PC 40.

[0087] By measuring the current level (I) simultaneously with the EDMR signal (current), the change in the EDMR signal (current) can be defined as ΔI, and sequential ΔI / I can be calculated by time-resolved measurement.

[0088] FIG. 7 shows a timing chart of time-resolved current measurement by the boxcar integrator 42. The capture gate of the boxcar integrator 42 is matched (references A and B in FIG. 7) to the position and width of a microwave pulse ("mwpulse" in FIG. 7) output in synchronization with a master clock whose repetition frequency is ω, and the section integrated values ​​of the current response signal and the luminescence response signal (signal indicated by reference number 130 in FIG. 7) from the sample 12 are continuously output from the boxcar integrator 42. If these values ​​are simultaneously measured for all of the EDMR method, ELDMR method, PCDMR method, and PLDMR method, it is possible to obtain the successive ratios (ΔI / I, ΔEL / EL (electroluminescence), ΔPC / PC (photo-current), ΔPL / PL (photoluminescence)) after the bias voltage pulse is applied to the sample 12. As a result, it is possible to determine how the proportion of electron spins involved in the macroscopic functions (current and luminescence) of the sample 12 changes over time. This function can be applied to all the measurement methods described below.

[0089] (Time-resolved ELDMR method) The configuration and operation of the ESR measurement apparatus 10 for implementing the time-resolved ELDMR method will be described.

[0090] According to the time-resolved ELDMR method, an emission signal is measured as a response signal to a bias voltage pulse from the sample 12. To perform the time-resolved ELDMR method, the ESR measurement apparatus 10 includes a photodetector 46, a preamplifier 48, a bandpass filter 50, a lock-in amplifier 52, an ADC 54, a PC 56, a boxcar integrator 58, and an ADC 60, as shown in FIG.

[0091] The photodetector 46 detects the light emitted from the sample 12. The detected emission signal is amplified by a preamplifier 48, passes through a bandpass filter 50 with a center frequency of 2ω, and is input to a lock-in amplifier 52. The bandpass filter 50 has the same function as the bandpass filter 34 described above.

[0092] The lock-in amplifier 52 receives a reference signal repeatedly sent from the multi-channel arbitrary waveform generator 20 at a frequency of 2ω, and selectively detects with high sensitivity only the components due to ESR from the response signal of the sample 12 to the bias voltage pulse, in the same manner as in the time-resolved EDMR spectrum measurement.

[0093] The magnetic field B is swept, and the value of the 2ω component detected by the lock-in amplifier 52 for the swept magnetic field B value is converted to a digital signal by the ADC 54 and then processed by the PC 56. This generates an ELDMR spectrum.

[0094] The time-resolved method is the same as that of the time-resolved EDMR method described above. That is, in the time-resolved ELDMR method, the measurement method A or the measurement method B described above is performed to obtain a time-resolved ELDMR spectrum or a time-resolved ELDMR signal.

[0095] The photodetector 46, the preamplifier 48 and the lock-in amplifier 52 constitute an example of a measuring means.

[0096] The ESR measuring device 10 also includes a boxcar integrator 58 connected to the preamplifier 48. The signal output from the preamplifier 48 is input to the boxcar integrator 58. The boxcar integrator 58 extracts a current level (EL) obtained when the microwave pulse is irradiated to the sample 12 from an emission signal obtained from the sample 12 in response to application of a bias voltage pulse to the sample 12. An ADC 60 is connected to the boxcar integrator 58, and the current level (EL) extracted by the boxcar integrator 58 is converted into a digital signal by the ADC 60 and output to the PC 56. The boxcar integrator 58 is included in an example of a measuring means.

[0097] By measuring the current level (EL) simultaneously with the ELDMR signal (current), the signal intensity of the ELDMR can be taken as ΔEL, and successive ΔEL / EL can be calculated by time-resolved measurement.

[0098] The timing chart for the time-resolved emission intensity measurement by the boxcar integrator 58 is the same as the timing chart shown in FIG.

[0099] It is possible to simultaneously perform the time-resolved EDMR method and the time-resolved ELDMR method. When performing only the time-resolved EDMR method without performing the time-resolved ELDMR method, the ESR measurement apparatus 10 does not need to include the photodetector 46, the preamplifier 48, the bandpass filter 50, the lock-in amplifier 52, the ADC 54, the PC 56, the boxcar integrator 58, and the ADC 60. When performing only the time-resolved ELDMR method without performing the time-resolved EDMR method, the ESR measurement apparatus 10 does not need to include the preamplifier 32, the bandpass filter 34, the lock-in amplifier 36, the ADC 38, the PC 40, the boxcar integrator 42, and the ADC 44.

[0100] (Time-resolved PCDMR method) The configuration and operation of the ESR measurement apparatus 10 for implementing the time-resolved PCDMR method will be described.

[0101] When performing the time-resolved PCDMR method, two types of methods for driving the sample 12 are considered.

[0102] One method is to apply a bias voltage pulse repeatedly to the sample 12 while steadily irradiating the sample 12 with excitation light from the laser light source 62 shown in FIG. 1, and to measure the response from the sample 12 as a current signal by amplifying it with the preamplifier 32, similar to the above-mentioned EDMR method.

[0103] The other method is to repeatedly irradiate the sample 12 with pulsed excitation light (hereinafter referred to as "bias light pulse") by a laser light source 62 while steadily applying a bias voltage to the sample 12. The bias light pulse is a rectangular pulse with a duty of 50%, similar to the bias voltage pulse shown in Fig. 2, and its repetition frequency is frequency ω.

[0104] The time-resolved method is the same as that of the time-resolved EDMR method described above. That is, in the time-resolved PCDMR method, the above-mentioned measurement method A or measurement method B is performed to obtain a time-resolved PCDMR spectrum or a time-resolved PCDMR signal.

[0105] (Time-resolved PLDMR method) The configuration and operation of the ESR measurement apparatus 10 for implementing the time-resolved PLDMR method will be described.

[0106] When performing the time-resolved PLDMR method, two types of methods for driving the sample 12 are possible, similar to the time-resolved PCDMR method.

[0107] In the PLDMR method, as in the ELDMR method described above, light emitted from the sample 12 is detected, and therefore the spectrum is measured in the same manner as in the ELDMR method.

[0108] The time-resolved method is the same as the time-resolved EDMR method described above.

[0109] It is possible to simultaneously perform the time-resolved PCDMR and time-resolved PLDMR.

[0110] <Second embodiment> An ESR measuring apparatus according to the second embodiment will be described with reference to Fig. 8. Fig. 8 shows an example of the configuration of an ESR measuring apparatus 10A according to the second embodiment.

[0111] In the ESR measurement apparatus 10 according to the first embodiment, a band-pass filter 34 is provided in front of a lock-in amplifier 36, and a band-pass filter 50 is provided in front of a lock-in amplifier 52. The band-pass filters 34 and 50 are band-pass filters centered on a frequency 2ω that is twice the frequency ω of the bias voltage pulse applied to the sample 12.

[0112] In the ESR measurement apparatus 10A according to the second embodiment, the repetition frequency of the device driving pulse (bias voltage pulse or device light pulse) repeatedly supplied to the sample 12 is 2ω, and the repetition frequency of the microwave pulse is ω. Furthermore, a low-pass filter 70 is provided in front of the lock-in amplifier 36 instead of the band-pass filter 34, and a low-pass filter 72 is provided in front of the lock-in amplifier 52 instead of the band-pass filter 50. The low-pass filters 70 and 72 are low-pass filters that pass only components with a frequency equal to or lower than ω.

[0113] Hereinafter, the bias voltage pulse and the device light pulse will be collectively referred to as a "device driving pulse."

[0114] The ESR measuring apparatus 10A according to the second embodiment has the same configuration as the ESR measuring apparatus 10 according to the first embodiment, except for the low-pass filters 70 and 72.

[0115] The difference between the BPF-2ω method, which is the measurement method of the first embodiment, and the LPF-ω method, which is the measurement method of the second embodiment, is the repetition frequency of the device driving pulse and the microwave pulse supplied to the sample 12.

[0116] In the BPF-2ω system according to the first embodiment, the repetition frequency of the device driving pulse and the microwave pulse synchronized with the master clock is the same frequency ω. In the LPF-ω system according to the second embodiment, the repetition frequency of the device driving pulse is frequency 2ω, and the repetition frequency of the microwave pulse is frequency ω. That is, in the second embodiment, the device driving pulse is repeatedly supplied to the sample 12 according to the frequency 2ω, and the microwave pulse is repeatedly irradiated to the sample 12 according to the frequency ω.

[0117] Fig. 9 shows each signal according to the second embodiment. The horizontal axis in Fig. 9 represents time.

[0118] Fig. 9(a) shows the on / off timing of the master clock generated by the multi-channel arbitrary waveform generator 20. Fig. 9(b) shows the timing when the arbitrary waveform generator 18 applies a device drive pulse (bias voltage pulse or bias light pulse) to the sample 12. Fig. 9(c) shows the timing when a microwave pulse is irradiated to the sample 12. Figs. 9(d) and 9(e) show the waveforms of signals emitted from the sample 12 in response to the irradiation of a microwave pulse. As in the first embodiment, the signal emitted from the sample 12 is either a current, a voltage, or an emission intensity depending on the type of the sample 12 (i.e., the device).

[0119] As shown in Figures 2(b) and 2(c), in the first embodiment, the repetition frequencies of the device driving pulse and the microwave pulse are the same frequency ω, whereas, as shown in Figures 9(b) and 9(c), in the second embodiment, the frequency of the device driving pulse is frequency 2ω and the frequency of the microwave pulse is frequency ω.

[0120] FIG. 10 shows each frequency component of the response signal generated from the sample 12 when the resonance condition is not satisfied. FIG. 11 shows each frequency component of the response signal generated from the sample 12 when the resonance condition is satisfied. As shown in FIG. 10 and FIG. 11, the harmonics of the response signal in non-resonance (i.e., the response signal when the resonance condition is not satisfied) and the harmonics of the response signal in resonance (i.e., the response signal when the resonance condition is satisfied) are all components of 2ω or more. Therefore, by passing only the ω component signal by the low-pass filters 70 and 72, as shown in FIG. 12, it is possible to selectively detect only the ESR response component, similar to the BPF-2ω method of the first embodiment. The frequency of the reference signal of the lock-in amplifiers 36 and 52 is ω.

[0121] According to the LPF-ω method of the second embodiment, a signal with higher sensitivity can be obtained compared to the BPF-2ω method of the first embodiment.

[0122] In the BPF-2ω method of the first embodiment, when the response waveform of the sample 12, which is a device, is affected by the entire circuit and receives linear distortion, odd-numbered harmonics are not obtained as expected, and integer-numbered harmonic components may be generated. Therefore, regardless of whether the signal is resonant or non-resonant, a slight 2ω component is constantly mixed into the signal, narrowing the dynamic range of the lock-in detection.

[0123] On the other hand, in the LPF-ω method of the second embodiment, all such distortion components are reflected in harmonic components of 2ω or more and are not mixed into the ω component. Therefore, the ω component is composed of only components involved in ESR resonance, and signals involved in ESR resonance can be detected with higher sensitivity than in the first embodiment.

[0124] The time resolution method is the same as the method (measurement methods A and B) according to the first embodiment. FIG. 13 shows measurement methods A and B according to the second embodiment. FIG. 13(a) shows the on / off timing of the master clock. FIG. 13(b) and FIG. 13(d) show the timing of supplying a device driving pulse to the sample 12. FIG. 13(c) and FIG. 13(e) show the timing of irradiating the sample 12 with a microwave pulse. The horizontal axis in FIG. 13 is time.

[0125] 13(b) and 13(c) are diagrams illustrating measurement method A. Figures 13(d) and 13(e) are diagrams illustrating measurement method B.

[0126] Measurement methods A and B according to the second embodiment are basically the same as measurement methods A and B according to the first embodiment, but in the second embodiment, the repetition frequency of the device driving pulse is 2ω and the repetition frequency of the microwave pulse is ω. The other conditions are the same as those in the first embodiment.

[0127] 14 shows the measurement results by the time-resolved ELDMR method. The measurement results were obtained by the LPF-ω method according to the second embodiment and the measurement method B. Delay in FIG. 14 indicates the delay time t d and the horizontal axis represents the magnetic field.

[0128] According to the above-mentioned first embodiment, by using a square wave with a duty of 50% as the power (current, voltage) or light pulse for driving the device sample 12, components unrelated to ESR resonance are obtained as harmonic components that are odd multiples of the frequency of the pulse. By selectively detecting the phase of only the integer multiple harmonic components due to the slight distortion effect caused by ESR resonance, it is possible to selectively and sensitively detect the conduction phenomenon involving electron spin.

[0129] According to the second embodiment described above, by using a square wave with a duty of 50% and a pulse with a frequency twice the repetition frequency (2ω) of the microwave pulse as the power (current, voltage) or light pulse for driving the device sample 12, all harmonic components of 2ω or more are obtained as response components unrelated to electron spin. By removing the harmonic components of 2ω or more with a low-pass filter, it is possible to selectively and sensitively detect a conduction phenomenon involving electron spin, as in the first embodiment.

[0130] Furthermore, in the first and second embodiments, the on-timing of the device driving pulse (i.e., the timing of applying a voltage to the sample 12 or the timing of irradiating the sample 12 with light) and the on-timing of the microwave pulse (i.e., the timing of irradiating the sample 12 with a microwave pulse) are relatively shifted to measure a plurality of time-series spectra, thereby making it possible to measure a time-resolved ESR spectrum responsive to the driving of the sample 12. A delay time td of the microwave pulse may be set and a plurality of time-series spectra may be measured by changing the delay time td, or a phase difference Δφ of the device driving pulse may be changed to measure a plurality of time-series spectra.

[0131] As described above, according to the first and second embodiments, by devising the shape of the device driving pulse and providing a difference in the method of generating harmonics, it is possible to selectively measure a weak ESR-derived signal that cannot be distinguished from a raw transient response signal detected by the conventional time-resolved ESR method with high sensitivity and in a time-resolved manner. The electronic state and reaction rate in the initial process of device function expression cannot be detected by the conventional method, but according to the first and second embodiments, such electronic state and reaction rate can be detected and analyzed.

[0132] <Modification> In the first embodiment described above, the repetition frequency of the device driving pulse and the repetition frequency of the microwave pulse are the same frequency ω, and in the second embodiment, the repetition frequency of the device driving pulse is twice the repetition frequency of the microwave pulse. In this way, the repetition frequency of the device driving pulse is a frequency having a height equal to or higher than the repetition frequency of the microwave pulse. When time resolution is not performed, the repetition frequency of the device driving pulse may be a frequency other than one or two times the repetition frequency of the microwave pulse, and may be a frequency higher than the repetition frequency of the microwave pulse. Even when the device driving pulse is supplied to the sample 12 according to such a frequency, the minute fluctuation component 100 shown in FIG. 2 and FIG. 9 can be detected.

[0133] In the first and second embodiments described above, the device driving pulse is a rectangular pulse, but when time resolution is not performed, the waveform of the voltage or light supplied to the sample 12 may have any shape other than a rectangular shape (for example, a sine curve, etc.). Even in this case, the minute fluctuation component 100 can be detected. [Explanation of symbols]

[0134] 10,10A ESR measuring apparatus, 12 sample, 14 cavity, 16 electromagnet, 18,22 arbitrary waveform generator, 20 multi-channel arbitrary waveform generator, 26 microwave oscillator, 30 circulator, 32,48 preamplifier, 34,50 bandpass filter, 36,52 lock-in amplifier, 62 laser source, 70,72 lowpass filter.

Claims

1. A static magnetic field generator that generates a static magnetic field; a cavity disposed within the static magnetic field, housing a sample responsive to the application of a voltage or light, and adapted to receive microwaves to produce electron spin resonance in the sample; A microwave irradiation means for repeatedly irradiating the sample with microwaves; A supplying means for repeatedly supplying a voltage or light to the sample in synchronization with the irradiation of the microwave to drive the sample; A measuring means for measuring a signal reflecting electron spin resonance generated in the sample; Including, The repetition frequency of the voltage or light supply is equal to or greater than the repetition frequency of the microwave irradiation; the measuring means includes a filter that extracts a specific frequency component from a signal obtained from the sample in response to the supply of a voltage or light, and measures the specific frequency component as a signal reflecting electron spin resonance. Electron spin resonance measuring device characterized by:

2. 2. The electron spin resonance measurement apparatus according to claim 1, The filter is a band-pass filter or a low-pass filter. Electron spin resonance measuring device characterized by:

3. A static magnetic field generator that generates a static magnetic field; a cavity disposed within the static magnetic field, housing a sample responsive to the application of a voltage or light, and adapted to receive microwaves to produce electron spin resonance in the sample; A microwave irradiation means for repeatedly irradiating the sample with microwaves; A supplying means for repeatedly supplying a voltage or light to the sample in synchronization with the irradiation of the microwave to drive the sample; A measuring means for measuring a signal reflecting electron spin resonance generated in the sample; Including, The repetition frequency of the voltage or light supply is equal to or greater than the repetition frequency of the microwave irradiation; The supplying means repeatedly supplies a voltage pulse or a light pulse to the sample; The voltage pulse or light pulse is a square wave with a duty cycle of 50%. The microwave irradiation means repeatedly irradiates the sample with microwave pulses having a pulse width other than a duty ratio of 50%. Electron spin resonance measuring device characterized by:

4. 4. The electron spin resonance measuring apparatus according to claim 3, The repetition frequency of the supply of the voltage pulse or the light pulse is the same as the repetition frequency of the irradiation of the microwave pulse; the measuring means extracts a specific frequency component from a signal obtained from the sample in response to the supply of a voltage pulse or an optical pulse using a band-pass filter having a center frequency that is twice the repetition frequency, and measures the specific frequency component as a signal caused by electron spin resonance. Electron spin resonance measuring apparatus characterized by:

5. 4. The electron spin resonance measuring apparatus according to claim 3, The repetition frequency of the supply of the voltage pulse or the light pulse is twice the repetition frequency of the irradiation of the microwave pulse, the measuring means extracts a specific frequency component equal to or lower than a repetition frequency of the microwave pulse irradiation from a signal obtained from the sample in response to the supply of a voltage pulse or an optical pulse using a low-pass filter, and measures the specific frequency component as a signal caused by electron spin resonance; Electron spin resonance measuring apparatus characterized by:

6. The electron spin resonance measurement apparatus according to any one of claims 3 to 5, the microwave irradiation means irradiates the sample with a microwave pulse by delaying the timing of irradiating the sample with the microwave pulse based on the timing of supplying a voltage pulse or a light pulse to the sample, and changes the timing of irradiating the microwave pulse for each measurement. Electron spin resonance measuring apparatus characterized by:

7. The electron spin resonance measurement apparatus according to any one of claims 3 to 5, the supplying means supplies a voltage pulse or a light pulse to the sample by delaying the timing of supplying a voltage pulse or a light pulse to the sample based on the timing of supplying a microwave pulse to the sample, and changes the timing of supplying a voltage pulse or a light pulse for each measurement. Electron spin resonance measuring apparatus characterized by:

8. The electron spin resonance measurement apparatus according to any one of claims 3 to 5, The measuring means further calculates an integrated value of a signal obtained from the sample in response to the supply of a voltage pulse or a light pulse. Electron spin resonance measuring apparatus characterized by:

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