In-situ sample rod of transmission electron microscope

Abstract

The invention relates to the technical field of transmission electron microscopes, in particular to an in-situ sample rod of a transmission electron microscope. The transmission electron microscope in-situ sample rod comprises a rod body, a chip, an optical fiber and an acquisition assembly. The chip is carried on the rod head at one end of the rod body and is used for loading and heating a sample; the sample can radiate infrared light at a high-temperature section of 700 DEG C and above. The optical fiber penetrates through the rod body, and one end of the optical fiber forms an input end and extends to one side of the sample so as to receive infrared light radiated by the sample; the other end of the optical fiber extends out of the rod tail and forms an output end so as to output infrared light towards the acquisition assembly. The acquisition assembly can acquire the light intensity of the infrared light with the two different wavelengths emitted by the sample, so that the light intensity ratio, namely the brightness ratio, of the infrared light with the two different wavelengths emitted by the sample can be obtained, the temperature T of the sample in the high-temperature section is calculated according to a double-color temperature measurement formula, and then high-precision temperature measurement of the sample in the high-temperature section is achieved.

Description

Technical Field

[0001] This application relates to the field of transmission electron microscopy, and in particular to an in-situ sample holder for transmission electron microscopy. Background Technology

[0002] In-situ heating is one of the important techniques in transmission electron microscopy (TEM) research. Specifically, it involves applying a temperature field to the sample inside the TEM to observe the structural evolution and behavioral characteristics of the sample in real time under high temperature conditions. This technique plays a key role in the research of high-temperature alloys, ceramics, and aerospace materials. Precise temperature control and measurement are directly related to the reliability of experimental data and the accuracy of scientific conclusions.

[0003] Currently, in-situ heating and temperature measurement in transmission electron microscopy mainly employ two technical solutions: one is based on a micro-area heating chip method, which integrates platinum or molybdenum metal resistance wires on the chip and calculates the temperature by measuring the resistance change of the resistance wires; the other is to heat the sample as a whole using a crucible heating method and monitor the temperature using thermocouples installed near the heating area. The thermocouple temperature measurement principle is based on the Seebeck effect, which states that in a circuit composed of two different metals, there is a corresponding relationship between the thermoelectric potential caused by the temperature gradient and the temperature difference.

[0004] However, both methods have significant limitations in the high-temperature range (>700°C). For micro-heated chips, the resistance-temperature relationship of platinum / molybdenum metals exhibits nonlinear characteristics in the high-temperature region, and is affected by factors such as material purity, lattice defects, recrystallization, and the processing technology during chip fabrication (including nanoscale edge burrs and defects of metal wires), resulting in large conversion uncertainties. As for the thermocouple temperature measurement method with crucible heating, due to issues such as thermoelectric drift, oxidation loss, and thermal contact resistance of the thermocouple material at high temperatures, its measurement accuracy decreases sharply with increasing temperature, and the systematic error is significantly greater than that of the micro-heating method. Summary of the Invention

[0005] The purpose of this invention is to provide an in-situ sample holder for transmission electron microscopy, which can improve the accuracy of real-time temperature measurement to a certain extent when observing the evolution of the microstructure of a sample at high temperatures.

[0006] This invention provides an in-situ sample holder for transmission electron microscopy, comprising a holder body, a chip, an optical fiber, and a data acquisition component; The rod has a rod head and a rod tail at both ends along its length. The chip is mounted on the rod head and is used to load and heat the sample. The optical fiber is inserted inside the rod body. One end of the optical fiber forms an input end and extends to the sample to receive the infrared light emitted by the sample. The other end of the optical fiber extends out of the rod tail and forms an output end. The acquisition component is located at the end of the rod, and the output end is used to output infrared light toward the acquisition component, and the acquisition component is used to obtain the light intensity of two infrared lights of different wavelengths.

[0007] Furthermore, one end of the optical fiber extending from the tail of the rod is connected to a beam splitter, so that the output ends of the optical fiber form a first output end and a second output end that are separated from each other, and the beam splitting ratio of the beam splitter is 50:50.

[0008] Furthermore, the acquisition component includes a first filter, a first photodetector, a second filter, and a second photodetector; The first photodetector is disposed opposite to the first output terminal, and the first filter is disposed between the first output terminal and the first photodetector. It is used to filter the infrared light output by the first output terminal into infrared light with wavelength λ1 and transmit it to the first photodetector to obtain the light intensity of the infrared light with wavelength λ1. The second photodetector is disposed opposite to the second output terminal, and the second filter is disposed between the second output terminal and the second photodetector. It is used to filter the infrared light output by the second output terminal into infrared light with a wavelength of λ2 and transmit it to the second photodetector to obtain the light intensity of the infrared light with a wavelength of λ2. λ1 is not equal to λ2.

[0009] Furthermore, the pole end is provided with an opaque light shield, the optical fiber extends into the light shield, and the acquisition component is located inside the light shield.

[0010] Furthermore, it also includes a host computer, and the acquisition component is communicatively connected to the host computer.

[0011] Furthermore, the input end of the optical fiber is coated with a conductive dielectric layer.

[0012] Furthermore, the distance between the input end of the optical fiber and the sample is 100 nm to 400 nm.

[0013] Furthermore, a clamping member is provided on the pole head, and the input end of the optical fiber is clamped between the clamping member and the pole head, and the position of the clamping member on the pole head is adjustable.

[0014] Furthermore, the chip is provided with a thin-film window that is transparent to the electron beam for holding the sample; The chip is equipped with heating electrodes for heating the sample.

[0015] Furthermore, the chip is provided with electrical measurement electrodes for performing electrical measurements on the sample; The chip is equipped with a resistance detection element for detecting the resistance of the heating material of the heating electrode.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The transmission electron microscope (TEM) in-situ sample holder provided by this invention includes a holder body, a chip, an optical fiber, and a data acquisition component. The holder body has a head and a tail at its two ends along its length. The chip is mounted on the head and is used to load the sample and heat it during detection. When heated to 700°C or higher, the sample emits infrared light. The optical fiber is inserted into the holder body. One end of the fiber extends from the head end of the holder body, forming an input end that extends to one side of the sample to receive the infrared light emitted by the sample. The other end of the fiber extends from the tail end, forming an output end for outputting infrared light. The output end of the fiber is opposite the data acquisition component located at the tail end, allowing the infrared light emitted by the sample to be guided through the fiber and propagated to the data acquisition component. The data acquisition component can acquire the light intensities of two different wavelengths of infrared light emitted by the sample, thereby obtaining the intensity ratio (brightness ratio) of the two different wavelengths of infrared light emitted by the sample. Based on the dual-color thermometry formula, the temperature T of the sample in the high-temperature range is calculated, thus achieving high-precision temperature measurement of the sample in the high-temperature range. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of the in-situ sample holder for transmission electron microscopy provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the chip structure provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the rod head of the in-situ transmission electron microscope sample provided in an embodiment of the present invention.

[0019] Figure label: 1-Vacuum chamber of transmission electron microscope; 2-Sample loading position; 3-Probe head; 4-Fiber optic cable; 5-Probe body; 6-Probe tail; 7-Light shield; 8-Spectrometer; 9-First filter; 10-Second filter; 11-First photodetector; 12-Second photodetector; 13-Chip; 14-Thin film window; 15-Heating electrode; 16-Host computer. Detailed Implementation

[0020] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0021] The components of the embodiments of the invention described and shown in the accompanying drawings can typically be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0022] Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] The following reference Figures 1 to 3 This application describes a transmission electron microscope in-situ sample holder according to some embodiments.

[0026] This application provides an in-situ sample holder for transmission electron microscopy (TEM) for in-situ heating experiments on samples in a TEM, and enables high-precision temperature measurement of samples in the high-temperature range (≥700℃).

[0027] Specifically, based on the principle of thermal radiation, when a sample is heated to 700°C or higher, it will emit infrared light, and the intensity of this infrared light follows Planck's law (blackbody radiation law) in relation to its wavelength. This application utilizes dual-color thermometry to invert the temperature by detecting the ratio of infrared light emitted by the sample at two different wavelengths, thereby achieving accurate measurement of the sample temperature.

[0028] The formulas for calculating blackbody radiation and temperature are explained below: The monochromatic radiance L(λ, T) of a blackbody at wavelength λ and temperature T satisfies Planck's formula:

[0029] Where C1 is the first radiation constant and C2 is the second radiation constant.

[0030] when (Shortwave or high temperature) index The formula can be simplified to the Wien approximation:

[0031] Two wavelengths, λ1 and λ2, are selected to measure the brightness L1 and L2 of the infrared light emitted by the target (i.e., the sample) at these two wavelengths, and the brightness ratio R is calculated:

[0032] Taking the logarithm of both sides of the above formula and rearranging, we can solve for the temperature T:

[0033] This is the core formula for dual-color thermometry. The temperature is only related to the ratio of the brightness of the two wavelengths of infrared light, and is independent of the emissivity of the target (provided that the emissivity of the target is equal at λ1 and λ2).

[0034] Next, we will refer to Figures 1 to 3 This application describes a transmission electron microscope in-situ sample holder according to some embodiments.

[0035] like Figures 1 to 3 As shown, the in-situ sample holder for transmission electron microscopy includes a holder 5, a chip 13, an optical fiber 4, and a data acquisition assembly.

[0036] One end of the rod 5 along its length is provided with a rod head 3, and the other end of the rod 5 along its length is provided with a rod tail 6. The end of the rod 5 with the rod head 3 is used to insert into the vacuum chamber 1 of the transmission electron microscope. The rod head 3 has a sample loading position 2 for mounting a chip 13. The chip 13 is used to load the sample and heat the sample during detection. As mentioned above, the sample can emit infrared light when heated to 700°C or above.

[0037] An optical fiber 4 is inserted into the rod body 5. One end of the optical fiber 4 extends from the end of the rod body 5 with the rod head 3, forming an input end. The input end of the optical fiber 4 extends to one side of the sample to receive the infrared light emitted by the sample. The other end of the optical fiber 4 extends from the rod tail 6, forming an output end for outputting infrared light. The output end of the optical fiber 4 is opposite to the acquisition component located at the rod tail 6, allowing the infrared light emitted by the sample to be guided through the optical fiber 4 and propagated to the acquisition component. The acquisition component can acquire the light intensity of two different wavelengths of infrared light emitted by the sample, such as the light intensity (light signal intensity) of infrared light with wavelengths of 700 nm and 900 nm. This allows the acquisition component to obtain the light intensity ratio of the two different wavelengths of infrared light emitted by the sample, i.e., the brightness ratio R. Based on the aforementioned dual-color temperature measurement formula, the temperature T of the sample in the high-temperature range is calculated with high accuracy, thus achieving high-precision temperature measurement of the sample in the high-temperature range.

[0038] In one embodiment of this application, preferably, one end of the optical fiber 4 extending from the rod tail 6 is connected to a beam splitter 8, so that the optical fiber 4 forms two separate output ends, namely a first output end and a second output end, and the beam splitter 8 has a beam splitting ratio of 50:50, so that the optical fiber 4 outputs two beams of infrared light of equal intensity to the acquisition component through the first output end and the second output end.

[0039] The acquisition component is able to acquire the intensity of infrared light with wavelength λ1 from one beam of infrared light and the intensity of infrared light with wavelength λ2 from another beam of infrared light, where λ1 is not equal to λ2.

[0040] In this embodiment, preferably, the acquisition component includes a first filter 9 and a first photodetector 11. The first photodetector 11 is disposed opposite to the first output terminal. The first filter 9 is disposed between the first output terminal and the first photodetector 11. The first filter 9 is used to filter out stray light and only allows infrared light with wavelength λ1 output from the first output terminal to pass through and be incident on the first photodetector 11 so that the intensity of infrared light with wavelength λ1 emitted by the sample can be detected by the first photodetector 11.

[0041] The acquisition component also includes a second filter 10 and a second photodetector 12. The first photodetector 11 is disposed opposite to the second output terminal. The second filter 10 is disposed between the second output terminal and the second photodetector 12. The second filter 10 is used to filter out stray light and only allows infrared light with a wavelength of λ2 output from the second output terminal to pass through and be incident on the second photodetector 12, so that the intensity of the infrared light with a wavelength of λ2 emitted by the sample can be detected by the second photodetector 12.

[0042] In this embodiment, preferably, the in-situ sample holder of the transmission electron microscope also includes a host computer, and the acquisition component is communicatively connected to the host computer. Specifically, the first photodetector 11 and the second photodetector 12 are communicatively connected to the host computer so that the detection results can be uploaded to the host computer and the temperature of the sample can be calculated by the host computer.

[0043] In this embodiment, preferably, the rod tail 6 is connected to an opaque light shield 7, and the optical fiber 4 is sealed out from the rod tail 6 and directly enters the light shield 7. The acquisition components are all located inside the light shield 7 to avoid stray light interference that could affect the accuracy of the detection results.

[0044] In this embodiment, preferably, the input end of the optical fiber 4 is coated with a conductive dielectric layer, such as silver paste, so as to avoid the optical fiber 4 causing charge interference to the microscopic imaging of the sample in the transmission electron microscope.

[0045] In this embodiment, preferably, the input end of the optical fiber 4 is adjusted to a distance of 100nm to 400nm from the sample to ensure that the optical fiber 4 can stably receive the infrared light emitted by the sample.

[0046] Preferably, a clamping member is detachably connected to the rod head 3, and the input end of the optical fiber 4 can be clamped between the rod head 3 and the clamping member, thereby stably fixing the input end of the optical fiber 4 to one side of the sample to stably receive the infrared light radiated by the sample; at the same time, the position of the clamping member on the rod head 3 is adjustable so that the position of the light input end can be adjusted according to the position of the sample.

[0047] In this embodiment, preferably, the chip 13 is provided with a transparent thin film window 14 for holding the sample and allowing the electron beam of the transmission electron microscope to pass through, so as to enable imaging observation of the sample under the transmission electron microscope.

[0048] In this embodiment, preferably, the chip 13 is provided with a plurality of heating electrodes 15 for heating the sample. Preferably, the chip 13 is also provided with a resistance detection element for detecting the resistance of the heating material of the heating electrodes 15.

[0049] When conducting in-situ heating experiments on samples at low temperatures (below 700℃), the infrared light energy emitted by the sample is weak, making it difficult to detect the intensity of infrared light using the aforementioned dual-color infrared thermometry method. Therefore, this application utilizes the principle of the temperature coefficient of resistance of metals to detect the resistance of the heating wire in real time through a resistance detection element, thereby further calculating the sample temperature. Specifically, the heating wire is made of metals such as tungsten, molybdenum, or platinum. At low temperatures, the resistance of these materials has a good linear relationship with temperature, allowing the temperature of the heating wire to be calculated from its resistance. In practical applications, the temperature of the heating wire is almost equal to the temperature of the sample, accurately reflecting the actual temperature of the sample, thus achieving high-precision temperature measurement of the sample at low temperatures.

[0050] Therefore, when performing in-situ heating experiments on samples using the sample rod of this application, the temperature of the sample is detected using the resistance method (based on the TCR principle) in the low-temperature range (<700℃) because the infrared signal is too weak, and the resistance method is stable and sensitive; in the high-temperature range (≥700℃), the dual-color infrared thermometry method (based on Planck's law) is used because the resistance method may exhibit nonlinearity or drift, and the infrared signal is strong enough to avoid emissivity interference; thus, high-precision temperature measurement of the sample can be achieved in both the low-temperature and high-temperature ranges.

[0051] In this embodiment, preferably, the chip 13 is further provided with electrical measurement electrodes for performing electrical measurements on the sample, such as detecting electrical parameters like voltage, current, resistance, and conductance. Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A transmission electron microscope in-situ sample holder, characterized in that, Includes the pole, chip, optical fiber, and acquisition components; The rod has a rod head and a rod tail at both ends along its length. The chip is mounted on the rod head and is used to load and heat the sample. The optical fiber is inserted inside the rod body. One end of the optical fiber forms an input end and extends to the sample to receive the infrared light emitted by the sample. The other end of the optical fiber extends out of the rod tail and forms an output end. The acquisition component is located at the end of the rod, and the output end is used to output infrared light toward the acquisition component, and the acquisition component is used to obtain the light intensity of two infrared lights of different wavelengths.

2. The transmission electron microscope in-situ sample holder according to claim 1, characterized in that, One end of the optical fiber extending from the tail of the rod is connected to a beam splitter, so that the output ends of the optical fiber form a first output end and a second output end that are separated from each other, and the beam splitting ratio of the beam splitter is 50:

50.

3. The transmission electron microscope in-situ sample holder according to claim 2, characterized in that, The acquisition component includes a first filter, a first photodetector, a second filter, and a second photodetector; The first photodetector is disposed opposite to the first output terminal, and the first filter is disposed between the first output terminal and the first photodetector. It is used to filter the infrared light output by the first output terminal into infrared light with wavelength λ1 and transmit it to the first photodetector to obtain the light intensity of the infrared light with wavelength λ1. The second photodetector is disposed opposite to the second output terminal, and the second filter is disposed between the second output terminal and the second photodetector. It is used to filter the infrared light output by the second output terminal into infrared light with a wavelength of λ2 and transmit it to the second photodetector to obtain the light intensity of the infrared light with a wavelength of λ2. λ1 is not equal to λ2.

4. The transmission electron microscope in-situ sample holder according to claim 1, characterized in that, The pole end is equipped with an opaque light shield, the optical fiber extends into the light shield, and the acquisition component is located inside the light shield.

5. The transmission electron microscope in-situ sample holder according to claim 1, characterized in that, It also includes a host computer, and the acquisition component is communicatively connected to the host computer.

6. The transmission electron microscope in-situ sample holder according to claim 1, characterized in that, The input end of the optical fiber is coated with a conductive dielectric layer.

7. The transmission electron microscope in-situ sample holder according to claim 1, characterized in that, The distance between the input end of the optical fiber and the sample is 100 nm to 400 nm.

8. The transmission electron microscope in-situ sample holder according to claim 1, characterized in that, The pole head is provided with a clamping member, the input end of the optical fiber is clamped between the clamping member and the pole head, and the position of the clamping member on the pole head is adjustable.

9. The transmission electron microscope in-situ sample holder according to claim 1, characterized in that, The chip has a thin-film window that is transparent to the electron beam for holding the sample; The chip is equipped with heating electrodes for heating the sample.

10. The transmission electron microscope in-situ sample holder according to claim 9, characterized in that, The chip is equipped with electrical measurement electrodes for performing electrical measurements on the sample; The chip is equipped with a resistance detection element for detecting the resistance of the heating material of the heating electrode.

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