An in-situ x-ray spectroscopy characterization system with a wide energy range

Abstract

The application relates to a wide-energy-range in-situ X-ray spectroscopy characterization system, which comprises a first undulator and a second undulator, the first undulator is used for providing hard X-ray light, and a first light path through which a hard X-ray beam passes is formed, and the second undulator is used for providing soft X-ray light, and a second light path through which a soft X-ray beam passes is formed; on the first light path, a first deflection and focusing device and a first Si3N4 film window are sequentially arranged along the transmission direction of the hard X-ray beam; on the second light path, a second deflection and focusing device and a second Si3N4 film window are sequentially arranged along the transmission direction of the soft X-ray beam; when the hard X-ray beam passes through the first Si3N4 film window after being deflected and focused by the first deflection and focusing device, the soft X-ray beam passes through the second Si3N4 film window after being deflected and focused by the second deflection and focusing device, and the two beams irradiate the sample together, an amplifier is arranged downstream of the sample to amplify a photoelectric current signal, and in-situ characterization information of the sample is obtained. The application can realize super-wide-energy-range photon coverage.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of in-situ measurement of synchrotron X-ray spectroscopy, and more particularly to an in-situ X-ray spectroscopy characterization system covering a wide energy range. BACKGROUND

[0002] X-ray spectroscopy is used to analyze the valence state, energy level structure, coordination bond type and bond length, coordination atom type and number, etc. of the core atoms of functional materials by exciting the electrons in the occupied state orbit to the vacuum level or the conduction band level, thereby obtaining the fingerprint information of the atomic orbit and electron orbit of the element to be measured. Therefore, X-ray spectroscopy has element sensitivity and chemical valence sensitivity, and is a widely used characterization method in the fields of physics, chemistry and materials.

[0003] At present, X-ray spectroscopy based on synchrotron X-ray source or laboratory X-ray source at home and abroad has the problem of discontinuous photon energy, especially the lack of characterization method for medium-energy X-ray spectroscopy (photon energy in the range of 1500-3000 eV), and it is difficult to perform in-situ characterization of medium-energy spectroscopy. For example, the laboratory X-ray spectroscopy characterization platform mainly uses the intrinsic Kα fluorescence of Mg / Al / Cr / Ga targets (1254 eV / 1486 eV / 5415 eV / 9251 eV) to carry out X-ray photoelectron spectroscopy experiments, and the Kα characteristic fluorescence and bremsstrahlung radiation of W / Mo / Ag targets to carry out X-ray absorption spectroscopy experiments. That is, the X-ray spectroscopy based on synchrotron radiation at home and abroad is basically based on X-ray of a specific energy range, either soft X-ray spectroscopy (100 eV-1500 eV) or hard X-ray spectroscopy (3000 eV or more), and there is little wide-energy-range X-ray spectroscopy covering important elements in the fields of energy materials, environment and life science, etc. from lithium to polonium (period 2 to period 6) in the periodic table, especially Si / P / S / Cl (1839 eV / 2146 eV / 2472 eV / 2822 eV).

[0004] In order to realize the in-situ characterization of X-ray spectroscopy in a super-wide energy range, only the BESSY experimental station in Germany can realize the X-ray spectroscopy characterization in the photon energy range of 80 eV-10000 eV at present. However, the upper limit of the photon energy is only 10000 eV, which cannot cover noble metal elements such as Pt and Ir; and the in-situ spectroscopy test scheme is to fill the reaction gas in the sample reaction / test cavity, introduce a three-stage differential pumping system between the ultrahigh vacuum X-ray path and the high-pressure test cavity, and thus minimize the pollution of the reaction gas to the ultrahigh vacuum environment of the X-ray path. However, with the change of the test environment and the accumulation of the test time, the pollution of the reaction gas to the X-ray path, including the pollution to the X-ray mirror and the X-ray focusing mirror, becomes more and more serious, so that it is also difficult to realize the in-situ X-ray spectroscopy characterization of the solid-liquid system. SUMMARY

[0005] In order to solve the above problems in the prior art, the present application provides a wide-energy-range in-situ X-ray spectroscopy characterization system, which can realize the coverage of photons in a super-wide energy range of 1500 eV-22000 eV.

[0006] The wide-energy-range in-situ X-ray spectroscopy characterization system provided by the present application comprises a first undulator and a second undulator, the first undulator is used for providing hard X-ray light and forming a first light path through which a hard X-ray beam passes, and the second undulator is used for providing soft X-ray light and forming a second light path through which a soft X-ray beam passes; on the first light path, a first deflection and focusing device and a first Si3N4 film window are sequentially arranged along the transmission direction of the hard X-ray beam; on the second light path, a second deflection and focusing device and a second Si3N4 film window are sequentially arranged along the transmission direction of the soft X-ray beam; after the hard X-ray beam is deflected and focused by the first deflection and focusing device and passes through the first Si3N4 film window, the soft X-ray beam is deflected and focused by the second deflection and focusing device and passes through the second Si3N4 film window at the same time, and after the hard X-ray beam and the soft X-ray beam pass through the corresponding first Si3N4 film window and second Si3N4 film window at the same time, they irradiate the sample together, and an amplifier is arranged downstream of the sample to amplify the photocurrent signal and obtain the in-situ characterization information of the sample.

[0007] Further, the first undulator adopts an in-vacuum undulator for providing photons in an energy range of 1500 eV-22000 eV; and the second undulator adopts an elliptical polarization undulator for providing photons in an energy range of 130 eV-1500 eV.

[0008] Further, the period length of each magnet in the in-vacuum undulator is 24 mm, the number of periods is 65, and the total length is 1.56 m; and the peak value of the magnetic field of the in-vacuum undulator is 0.96 T, and the minimum distance between the north and south poles of the magnet is 6 mm.

[0009] Furthermore, the first deflection focusing device and the second deflection focusing device include a super-torsional cylindrical focusing lens and a matching motion adjustment mechanism.

[0010] Furthermore, the distance between the first Si3N4 membrane window and the second Si3N4 membrane window is 58 mm.

[0011] Furthermore, the diameter of the first Si3N4 film window and the thickness of the second Si3N4 film window are 5 mm and 100 nm respectively.

[0012] Furthermore, the first Si3N4 membrane window and the second Si3N4 membrane window are encapsulated on a vacuum flange, which is installed at the front end of the reaction test chamber.

[0013] Furthermore, the vacuum flange is installed 0.5m at the front end of the reaction test chamber.

[0014] Furthermore, the first Si3N4 film window is perpendicular to the propagation direction of the hard X-ray beam, and the second Si3N4 film window is perpendicular to the propagation direction of the soft X-ray beam.

[0015] Furthermore, a fluorescent target is provided at the sample location.

[0016] The present invention has the following beneficial effects:

[0017] 1) By optimizing the magnet spacing and magnetic field peak of the vacuum undulator, a maximum photon energy of 22000 eV was achieved;

[0018] 2) The ingenious design of introducing a double Si3N4 film window reduces the overall area of ​​the Si3N4 film and increases the pressure difference and pressure of the reactant gas that the film can withstand: the two independent Si3N4 film windows are responsible for physically isolating the vacuum environment of soft X-rays and hard X-rays from the high-pressure environment of the in-situ reaction / test chamber, while ensuring the normal passage of X-rays. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the wide-energy-range in-situ X-ray spectroscopic characterization system according to the present invention.

[0020] Figure 2 yes Figure 1 Schematic diagram of photon flux output of a medium vacuum internal undulator.

[0021] Figure 3(a) shows the core X-ray spectrum of Au(111) single crystal under 41 mbar Ar2 gas; Figure 3(b) shows the L3 edge X-ray absorption spectrum of Ru single crystal under 1 mbar.

[0022] Fig. 4(a) is a L3 edge absorption spectrum of Pr measured in an energy range of 5900eV~6300eV under an O2 atmosphere of 1mbar; Fig. 4(b) is a L3 edge absorption spectrum of Au in an energy range of 11000eV~12000eV. DETAILED DESCRIPTION

[0023] In order to make the purposes, schemes and advantages of the present application clearer, the specific structure and working principle of the present application are described in more detail below in combination with the drawings. The embodiments are only used to explain the present application and are not limited to the embodiments, nor are they used to limit the application range of the present application.

[0024] The following content is intended to make the public have a clearer understanding of the present application, and for those skilled in the art in the relevant field, the present application can be clearly understood even without the following detailed description.

[0025] As shown in Figure 1 The present application provides a wide-energy-range in-situ X-ray spectroscopy characterization system, which comprises a first undulator 10 and a second undulator 20. The first undulator 10 is used to provide hard X-ray light, forming a first light path through which a hard X-ray beam passes; the second undulator 20 is used to provide soft X-ray light, forming a second light path through which a soft X-ray beam passes.

[0026] The first undulator 10 and the second undulator 20 are independently arranged, so that the hard X-ray beam and the soft X-ray beam are two independent light paths. In the embodiment, the first undulator 10 is an in-vacuum undulator, which can provide continuously adjustable photons in an energy range of 1500eV~22000eV, as shown in Figure 2 The second undulator 20 is an elliptical polarization undulator, which can provide continuously adjustable photons in an energy range of 130eV~1500eV. In the in-vacuum undulator, the period length of each magnet is 24 mm, the number of periods is 65, and the total length is 1.56 m; and the peak value of the magnetic field of the in-vacuum undulator is 0.96 T, and the minimum distance between the north and south poles of the magnet is 6 mm.

[0027] On the first light path, a first deflection and focusing device 11 and a first Si3N4 film window 12 are arranged in sequence along the transmission direction of the hard X-ray beam; on the second light path, a second deflection and focusing device 21 and a second Si3N4 film window 22 are arranged in sequence along the transmission direction of the soft X-ray beam.

[0028] In the embodiment, the two deflection focusing devices 11, 21 are independently arranged identical devices, including hyper-ring cylindrical focusing mirrors and matching motion adjustment mechanisms, for respectively deflecting and focusing the hard X-ray beam and the soft X-ray beam, so that the deflected and focused two X-ray beams can converge at the same position of the sample 3. Through such design, the spot coincidence degree of the two X-ray beams can be 100%. Therefore, the full coverage of X-rays in the energy range of 130 eV-22000 eV can be realized at the same position of the sample.

[0029] Since one side of the Si3N4 film window is in an ultra-high vacuum environment (10 -9 mbar), and the other side is in a near-normal pressure reaction environment (100 mbar). In order to increase the pressure difference resistance of the Si3N4 film window, the thickness of the film needs to be increased, and in order to increase the penetration ability of the X-ray in the low-energy region (130 eV-1500 eV), the film cannot be too thick. At the same time, the larger the area of the film window is, the smaller the pressure difference resistance is, and the easier the film window is to break. Based on the above considerations, the application adopts a design of double Si3N4 film windows, the distance between the two Si3N4 film windows is 58mm±5mm, the diameter of each Si3N4 film window is 5mm±1mm, and the thickness is 100nm. The 100nm thick Si3N4 window film can ensure more than 50% of the soft X-ray to pass through. In this way, the design of a large whole Si3N4 film window can be avoided, the area of the film window can be effectively reduced, and the pressure difference between the two sides of the film window can be ensured. If a whole Si3N4 film window is used, considering that two independent X-rays of 130-1500eV and 1500-22000eV need to pass through at the same time, and the distance between the two beams, a Si3N4 film window with a diameter of 68mm needs to be designed, and the pressure resistance will be greatly reduced.

[0030] Moreover, the first Si3N4 film window 12 and the second Si3N4 film window 22 are packaged on a two-side hole vacuum flange, the vacuum flange packaging the two Si3N4 film windows is installed at a position 0.5m in front of the reaction test cavity, and the distance of 0.5m before the X-ray enters the reaction test cavity can ensure the uniformity of the reaction gas pressure in the cavity and the normal installation of other photoelectric elements. In addition, the first Si3N4 film window 12 is perpendicular to the propagation direction of the hard X-ray beam, and the second Si3N4 film window 22 is perpendicular to the propagation direction of the soft X-ray beam, so as to effectively increase the flux of the X-ray after passing through the SiN window film.

[0031] Under the above design, the hard X-ray beam passes through the first Si3N4 film window 12 after being deflected and focused by the first deflection focusing device 11, the soft X-ray beam passes through the second Si3N4 film window 22 after being deflected and focused by the second deflection focusing device 21, and the hard X-ray beam and the soft X-ray beam irradiate the sample 3 under the reaction condition after passing through the corresponding film window at the same time. The fluorescent target arranged at the sample 3 can monitor whether the two X-ray beams independently pass through the film window and reach the sample.

[0032] The downstream of sample 3 is provided with an amplifier 4, and high-quality X-ray absorption spectrum can be obtained by measuring the total photoelectric current signal (total electron yield) generated by the sample under X-ray irradiation and low-noise amplification, so as to obtain the intrinsic element information and chemical valence information of the sample.

[0033] The highest gas pressure in the reaction test cavity can reach 100 mbar, and the sample can be measured by X-ray spectroscopy under in-situ reaction conditions regardless of solid-gas environment or solid-liquid environment, effectively solving the characterization problem of wide energy region X-ray spectroscopy, especially the bottleneck of in-situ characterization of medium energy region X-ray spectroscopy.

[0034] The application realizes in-situ characterization of X-ray spectroscopy in a wide energy region, and the photon energy is from 130eV to 22000eV, especially in the energy region of 1500~3000eV. As shown in Fig. 3(a), based on Au(111) single crystal, the Au4f core state peak is measured by soft X-ray, wherein the spin-orbit splitting peak shape, half-width and peak area of 4f5 / 2 and 4f7 / 2 are consistent with the experimental results under the condition of ultra-high vacuum, which verifies the feasibility of the double-hole Si3N4 window film design and the robustness of the window film; as shown in Fig. 3(b), the Ru L3 edge X-ray absorption spectrum is measured by X-ray in the energy segment of 2820~2870eV under the reaction gas atmosphere of 1mbar CO2, and the right side appears obvious oxidation peak, which identifies the oxidation process of Ru in the CO2 reduction process, and verifies the reliability and applicability of the medium energy region spectroscopy.

[0035] Further, as shown in Fig. 4(a) and Fig. 4(b), the L3 edge absorption spectrum of rare earth metal Pr under 1mbar O2 reaction gas atmosphere is in-situ tested by hard X-ray in the energy region of 5900~6300eV, and the obvious oxidation component is found, which verifies the occurrence of oxidation reaction; the L3 absorption edge of Au is tested by absorption spectrum in the energy interval of 11900eV~12000eV, and it is found that in the hard X-ray energy region, the total electron yield can also obtain good X-ray absorption spectrum data. The above test data verifies the reliability and universality of in-situ X-ray spectroscopy in a wide energy region.

[0036] The above is only a preferred embodiment of the application, and is not intended to limit the scope of the application. The above embodiment of the application can be variously changed. Any simple, equivalent changes and modifications made according to the content of the claims and description of the application fall within the scope of protection of the patent. The application is not described in detail.

Claims

1. A wide-energy-range in-situ X-ray spectrography characterization system, characterized by, The application relates to a device for in-situ characterization of a sample, which comprises a first undulator and a second undulator, the first undulator is used for providing hard X-ray light, a first light path through which a hard X-ray beam passes is formed, the second undulator is used for providing soft X-ray light, a second light path through which a soft X-ray beam passes is formed; on the first light path, a first deflection focusing device and a first Si3N4 film window are sequentially arranged along the transmission direction of the hard X-ray beam; on the second light path, a second deflection focusing device and a second Si3N4 film window are sequentially arranged along the transmission direction of the soft X-ray beam; After the hard X-ray beam is deflected and focused by the first deflection focusing device and passes through the first Si3N4 film window, the soft X-ray beam is deflected and focused by the second deflection focusing device and passes through the second Si3N4 film window, the hard X-ray beam and the soft X-ray beam pass through the corresponding first Si3N4 film window and second Si3N4 film window at the same time and irradiate the sample at the same time, a magnifier is arranged downstream of the sample to amplify the photoelectric current signal and obtain in-situ characterization information of the sample; The first Si3N4 film window and the second Si3N4 film window are both 10 -9 mbar on one side and 100 mbar on the other side; the distance between the first Si3N4 film window and the second Si3N4 film window is 58 mm, the diameter of the first Si3N4 film window and the second Si3N4 film window is 5 mm, and the thickness is 100 nm, and the 100 nm thick Si3N4 window film can ensure more than 50% soft X-ray transmission.

2. The in situ X-ray spectrography characterization system of wide energy regions according to claim 1, characterized in that, The first undulator is a vacuum undulator and is used for providing photons in an energy range of 1500 eV to 22000 eV; the second undulator is an elliptical polarization undulator and is used for providing photons in an energy range of 130 eV to 1500 eV.

3. The in situ X-ray spectrography system of claim 2, wherein, The period length of each magnet in the vacuum undulator is 24 mm, the period number is 65, and the total length is 1.56 m; the peak value of the magnetic field of the vacuum undulator is 0.96 T, and the minimum distance between the north and south poles of the magnet is 6 mm.

4. The in situ X-ray spectrography characterization system of wide energy regions according to claim 1, characterized in that, The first deflection focusing device and the second deflection focusing device comprise super-ring cylindrical focusing mirrors and matched motion adjusting mechanisms.

5. The in situ X-ray spectrography characterization system of wide energy regions according to claim 1, characterized in that, The first Si3N4 film window and the second Si3N4 film window are packaged on a vacuum flange, and the vacuum flange is installed at the front end of a reaction test cavity.

6. The in situ X-ray spectrography system of claim 5, wherein, The vacuum flange is installed at a position 0.5 m away from the front end of the reaction test cavity.

7. The in situ X-ray spectrography characterization system of wide energy regions according to claim 1, characterized in that, The first Si3N4 film window is perpendicular to the propagation direction of the hard X-ray beam, and the second Si3N4 film window is perpendicular to the propagation direction of the soft X-ray beam.

8. The in situ X-ray spectrography characterization system of wide energy regions of claim 1, wherein, A fluorescent target is arranged at the sample.

Images