Device for detecting metallization transformation of substance under high pressure based on microwave technology

Abstract

The utility model relates to a microwave technology-based detection device and method for metallization transformation of substances under high voltage, the detection device is composed of a microwave generator, a DAC detection unit and a parameter detection device, and the DAC detection unit is respectively connected with the microwave generator and the parameter detection device through microwave transmission lines to realize signal transmission. The DAC detection unit is mainly composed of a microstrip line set, an upper diamond and a lower diamond, and the position with the optimal experiment effect is found by changing the width of the lower microstrip line in the DAC detection unit to measure an S parameter response simulation curve. According to the utility model, a mode of combining the microstrip antenna and the diamond anvil cell is adopted to realize the detection of the metallization transformation process of the material under high pressure, the device is simple and reliable in structure, low in power consumption, convenient and easy to use, the detection method is low in experiment cost, and the experiment steps are simple and easy to operate; and the gasket and the sample to be tested are convenient to replace, and the device can be used for researching the high-pressure scientific material metallization or material non-gold transformation process.

Description

TECHNICAL FIELD

[0001] The utility model belongs to high pressure physical property detection technical field, concretely relates to a kind of detection device of substance metallization transformation under high pressure based on microwave technology. BACKGROUND

[0002] High-pressure physics is a discipline that studies the physical behavior and property changes of matter under high or ultra-high pressure extreme conditions. Under high pressure conditions, the basic structure of matter changes due to the change of interaction force between atoms, showing many properties that the matter does not have. Therefore, high-pressure synthesis method is an important channel to obtain new materials. High-pressure physics has therefore played an extremely important role in promoting disciplines such as earth science, chemistry, condensed matter physics, materials science, and biological science.

[0003] Metallization transformation refers to the phenomenon that the electrical conductivity of certain materials changes from insulating state to metallic conduction state when they undergo changes in external conditions such as temperature, pressure, electric field, or chemical doping, often accompanied by structural phase transition. Currently, the most common method for detecting metallization transformation of substances under high pressure conditions in diamond anvil cell (DAC) is the four-probe method. The four-probe method has important applications in measuring the resistivity and conductivity of materials, especially in the study of semiconductors and metallization transformation. This method works by placing four electrodes on the sample and applying current and measuring voltage to calculate the resistivity of the material. Due to its high precision, wide applicability, and strong reliability, it is widely used in the study of material electrical properties. However, in high-pressure electrical property research, the four-probe (four-terminal) measurement technique requires metal electrodes to be plated on the diamond of the anvil, which is complex and difficult to process. Moreover, the electrodes are relatively fragile, limiting the application of higher pressure.

[0004] Over the past few decades, microwave technology has developed rapidly. Due to its high frequency and wide frequency band, it has become a research hotspot in technology applications. However, in the field of high-pressure science, the application of microwave technology is relatively limited. The existing technology discloses a high-pressure substance metallization transformation detection device based on microwave technology, which combines microwave resonant cavity with diamond anvil cell for detecting substance transformation under high pressure. Its detection principle is to use microwave signals to enter the resonant cavity, and when the wavelength of the microwave signal matches the size of the resonant cavity, resonance occurs, which detects the metallization transformation process of the substance, and determines the metal structure phase transition high-pressure transformation point of the sample to be detected. However, the resonant cavity is complex and expensive to manufacture. Therefore, to improve traditional high-pressure electromagnetic detection technology, there is an urgent need to develop a new type of device based on microwave technology to detect high-pressure metallization transformation of substances, to effectively solve the above problems. SUMMARY

[0005] The utility model discloses a novel device for detecting the metallization transformation of substance under high pressure based on microwave technology, which combines microstrip line with anvil, to solve the problem of detecting the electrical property change of substance under high pressure and assisting in the research of structural phase transition.

[0006] The utility model discloses a novel device for detecting the metallization transformation of substance under high pressure based on microwave technology, which combines microstrip line with anvil, to solve the problem of detecting the electrical property change of substance under high pressure and assisting in the research of structural phase transition.

[0007] A kind of substance metallization transformation detection device under high pressure based on microwave technology, by microwave generator 1, DAC detection unit 3 and parameter detection device 4 constitute;The DAC detection unit 3 is connected with microwave generator 1, parameter detection device 4 respectively by microwave transmission line 2, realizes the transmission of signal;

[0008] The DAC detection unit 3 is mainly composed of microstrip line group, upper diamond 15 and lower diamond 16;The upper diamond 15 and lower diamond 16 are symmetrically distributed on the upper and lower sides of the microstrip line group;DAC detection unit 3 also includes upper block 12 and lower block 13, and the upper block 12 and the lower block 13 are located on the upper and lower sides of the upper diamond 15 and the lower diamond 16 respectively;The bottom of the lower block 13 is provided with a tapered observation window 11;

[0009] The microstrip line group is composed of upper microstrip line 7 and lower microstrip line 9, the upper microstrip line 7 is installed on the upper diamond 15, the middle part of the lower microstrip line 9 serves as a high-voltage DAC gasket, a sample cavity 6 is arranged at the center of the gasket, and the upper diamond 15 is in contact with the sample cavity 6;The two sides of the microstrip line group are respectively provided with a signal input end 10 and a signal output end 8;The microwave generator 1 is connected with the signal input end 10 through the microwave transmission line 2, and microwave signals are transmitted into the microstrip line group through the signal input end 10.

[0010] Further, the upper microstrip line 7 has a hole and can be nested on the upper diamond 15.

[0011] Further, the middle circular part of the lower microstrip line 9 serves as a high-voltage DAC gasket, and a micropore is drilled at the center thereof as a sample cavity 6 for containing a sample to be measured doped with ruby powder.

[0012] Further, the signal input end 10 and the signal output end 8 are fixed with the microstrip line group by welding or using conductive silver glue.

[0013] Further, the upper supporting block 12 and the lower supporting block 13 are fastened by two bolts 5 and two studs 14, four bolt holes are symmetrically formed in four corners of the upper supporting block 12 and the lower supporting block 13, and the upper supporting block 12 and the lower supporting block 13 are supported and limited by the two bolts 5 passing through the corresponding bolt holes and being fastened with nuts.

[0014] Further, the microwave generator 1 is a vector analyzer or a controllable microwave voltage-controlled oscillator (VCO), and the parameter detection device 4 is a vector analyzer, a frequency meter or a detector.

[0015] Further, the microstrip line group is in the shape of an upper strip line and a lower strip line, and a circular ring structure with different radii is arranged in the middle of each strip line; the upper microstrip line 7 is a circular ring, and the lower microstrip line 9 is a disc with a hole, the length of each strip line is 6-8 cm, the width is 2-7 mm, the thickness is 0.2-1.1 mm, the outer diameter of the center circle of the upper microstrip line is 15-25 mm, the inner diameter is 0.2-3.5 mm, the outer diameter of the center circle of the lower microstrip line is 10-20 mm, and the inner diameter is 0.05-0.7 mm, the distance between the two microstrip lines is 1.5-3.5 mm, and the two ends of the microstrip line group are connected with SMA ports by welding or high-conductivity silver glue bonding and solidification.

[0016] Further, the length of each strip line is 6.32 cm, the thickness is 0.25 mm, the outer diameter of the center circle of the upper microstrip line is 18 mm, the inner diameter is 2.3 mm, the length of the two side strip parts is 22.6 mm, and the width is 3.09 mm, the outer diameter of the center circle of the lower microstrip line is 14 mm, the inner diameter is 0.46 mm, the length of the two side strip parts is 24.6 mm, and the width is 2.8 mm, and the distance between the two microstrip lines is 1.6 mm.

[0017] Further, the upper supporting block 12 and the lower supporting block 13 are made of metal materials with a radius of 2.8 cm and a height of 1.4 cm, the anvil surface radius of the upper diamond 15 and the lower diamond 16 is 50-700 μm, the height of the anvil is 2-5 mm, and the material of the upper microstrip line 7 and the lower microstrip line 9 used as a high-pressure DAC gasket is made of metal materials such as steel, tungsten, copper or rhenium with a thickness of 0.2-1.1 mm.

[0018] Compared with the prior art, the utility model has the advantages of:

[0019] The utility model discloses a microstrip antenna and diamond anvil cell combined mode is realized under high pressure to the detection of material metallization transformation process, and the detection device simple and reliable structure, low power consumption, convenient and easy to use, should the device detect, and the experimental cost is low, and the experimental procedure is simple and easy to operate, the gasket and the replacement of the sample to be detected are also more convenient in the utility model, can be used to the research of high pressure science material metallization or material non-metallic transformation process. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical scheme of the embodiment of the utility model, the following will be briefly introduced to the drawing needed to be used in the embodiment, and should understand, the following drawings only show some embodiments of the utility model, therefore should not be regarded as the limitation to the range, for ordinary skilled person in the art, under the premise of not paying the creative labor, can also obtain other related drawings according to these drawings.

[0021] Figure 1 It is the overall structural drawing of microwave technology metallization transformation;

[0022] Figure 2 It is the DAC detection unit structure diagram;

[0023] Figure 3 It is the microstrip line structure diagram, Figure 3 a is the upper microstrip line, Figure 3 b is the lower microstrip line;

[0024] Figure 4 It is the relationship curve diagram between the frequency difference Δf of the metallization transformation of metal and non-metal and the width w of microstrip line;

[0025] Figure 5 It is the relationship curve diagram between the parameter difference ΔS of the metallization transformation of metal and non-metal and the width w of microstrip line;

[0026] Figure 6 It is the relationship curve diagram between the parameter difference ΔS of the metallization transformation of metal and non-metal and the diameter difference ΔD of upper and lower discs;

[0027] Figure 7 It is the relationship curve diagram between the frequency difference Δf of the metallization transformation of metal and non-metal and the diameter difference ΔD of upper and lower discs;

[0028] Figure 8 It is the S12 parameter response curve simulation diagram corresponding when the detection device detects metal state and non-metal state.

[0029] In the figure, 1. Microwave generator 2. Microwave transmission line 3. DAC detection unit 4. Parameter detection device 5. Bolt 6. Sample cavity 7. Upper microstrip line 8. Signal output end 9. Lower microstrip line 10. Signal input end 11. Viewing window 12. Upper supporting block 13. Lower supporting block 14. Stud 15. Upper diamond 16. Lower diamond 17. Sample material. DETAILED DESCRIPTION

[0030] The utility model will be further described below in conjunction with examples:

[0031] The utility model will be further described below in conjunction with examples: It can be understood that the specific examples described here are only used to explain the utility model, and not limit the utility model. In addition, it should be noted that, in order to facilitate the description, only the part related to the utility model is shown in the drawing, not all structures.

[0032] It should be noted that: similar signs and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, in the description of the utility model, the terms "first", "second" and the like are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0033] The utility model adopts the mode of combining experiment and simulation, uses HFSS finite element simulation software to simulate the experimental detection results, and can analyze the influence of the change of DAC detection unit 3 relative to the diamond anvil position and the change of DAC detection unit 3 size on the experimental results through simulation; the best value of the width of DAC detection unit 3 and the radius and position of the middle plane disc is obtained, and then the corresponding spatial position of each element and the shape and size of DAC detection unit 3 with the best experimental effect are found.

[0034] As shown in Figure 1 The utility model discloses a high-pressure substance metallization transformation detection device based on microwave technology, which is composed of a microwave generator 1, a DAC detection unit 3 and a parameter detection device 4. The DAC detection unit 3 is connected with the microwave generator 1 and the parameter detection device 4 through microwave transmission lines 2 respectively, so as to realize signal transmission.

[0035] As shown in Figure 2 The DAC detection unit 3 is mainly composed of a microstrip line group, an upper diamond 15 and a lower diamond 16. The upper diamond 15 and the lower diamond 16 are symmetrically distributed on the upper and lower sides of the microstrip line group.

[0036] The microstrip line group is composed of an upper microstrip line 7 and a lower microstrip line 9. The upper microstrip line 7 has a hole and can be nested on the upper diamond 15. The lower microstrip line 9 has a circular portion in the middle (such asFigure 3 As shown in Figure b, the central circular component of the lower microstrip line 9 (excluding the two side strip-shaped portions) serves as a high-voltage DAC gasket, with a microhole drilled in its center serving as the sample cavity 6 for holding the test sample doped with ruby ​​powder. The top of the upper diamond 15 contacts the sample cavity 6. By changing the width of the lower microstrip line 9 in the DAC detection unit 3 and measuring the S-parameter response simulation curve, the position with the best experimental effect, i.e., the optimal size of the microstrip line in the DAC detection unit, is found. Specifically, the size of the microstrip line and the size of the sample cavity, including the two side strip-shaped portions and the central circular portion, are changed. Figure 4 , Figure 5 The change is to the width of the strip section. Figure 6 , Figure 7 The dimensions of the middle circular section were modified. The optimal position for experimental results refers to the curve. Figure 8 The optimal detection location is where the lower microstrip line has the most suitable size, where the S-parameter frequency and amplitude changes most significantly, resulting in the highest sensitivity. By finding this optimal location, high detection sensitivity and accuracy can be achieved when a material undergoes a metallization transition.

[0037] The microstrip line assembly has a signal input terminal 10 and a signal output terminal 8 on both sides, and the signal input terminal 10 and the signal output terminal 8 are fixed to the microstrip line assembly by welding or by using conductive silver paste.

[0038] The microwave generator 1 is connected to the signal input terminal 10 via the microwave transmission line 2, and transmits the microwave signal to the microstrip line group through the signal input terminal 10. When the transmitted microwave wavelength matches the parameters such as the size and shape of the microstrip line, the S-parameter curve of the microstrip line group will have obvious extreme values ​​(peaks or valleys), and the amplitude of the S-parameter at the maximum extreme value and its corresponding frequency value f can be obtained.

[0039] The parameter detection device 4 is connected to the signal output terminal 8 via a microwave transmission line 2, through which microwave signals are transmitted to the parameter detection device 4 for detection. The DAC detection unit 3 also includes an upper support block 12 and a lower support block 13. The upper support block 12 and the lower support block 13 are fastened by two bolts 5 and two studs 14. Specifically, both the upper support block 12 and the lower support block 13 are made of metal, and four bolt holes are symmetrically opened at the four corners of the upper support block 12 and the lower support block 13. Two bolts 5 are passed through the corresponding bolt holes and fastened to nuts to achieve support and limit of the upper support block 12 and the lower support block 13.

[0040] In this invention, in order to further observe the upper diamond 15, the lower diamond 16, the sample material 17, and the fluorescence spectrum detection, a conical observation window 11 is opened at the bottom of the lower support block 13.

[0041] The microwave generator 1 is a vector network analyzer or a controllable microwave voltage-controlled oscillator (VCO). The parameter detection device 4 is a vector network analyzer, a frequency meter or a detector.

[0042] For example, a vector network analyzer (VNA) can be used as the microwave generator 1 and the parameter detection device 4 to detect the S-parameter response signal curve. The vector network analyzer is a high-precision test instrument that can measure and analyze the amplitude, phase, frequency and other parameters of radio frequency (RF) and microwave signals. In the utility model, the vector network analyzer can be used as the microwave generator 1 and the parameter detection device 4 to generate a microwave signal and analyze the signal returned from the DAC detection unit 3. The S-parameter response curve of the system can be detected, that is, the relationship curve of the horizontal axis sweep frequency and the vertical axis S parameter.

[0043] Specifically, when the vector network analyzer is used as the microwave generator 1, the microwave transmission line 2 uses a coplanar strip line for transmission; the input and output ends use SMA conversion joints; and the parameter detection device 4 is also a vector network analyzer.

[0044] As shown in Figure 3 The upper microstrip line 7 is a circular ring, and the lower microstrip line 9 is a circular disc with a hole (the hole is a sample cavity). The length of the two strip lines is 6cm-8cm, the width is 2mm-7mm, and the thickness is 0.2mm-1.1mm. The outer diameter of the center circle of the upper microstrip line is 15mm-25mm, and the inner diameter is 0.2mm-3.5mm. The outer diameter of the center circle of the lower microstrip line is 10mm-20mm, and the inner diameter (hole diameter) is 0.05mm-0.7mm. The distance between the two microstrip lines is 1.5mm-3.5mm, and the two ends of the microstrip line group are connected with the SMA port by welding or high-conductivity silver glue bonding and curing.

[0045] Preferably, the length is 6.32cm, the thickness is 0.25mm, the outer diameter of the center circle of the upper microstrip line is 18mm, the inner diameter is 2.3mm, the length of the two side strip parts is 22.6mm, and the width is 3.09mm. The outer diameter of the center circle of the lower microstrip line is 14mm, the inner diameter is 0.46mm, the length of the two side strip parts is 24.6mm, and the width is 2.8mm. The distance between the two microstrip lines is 1.6mm. The above is the optimal position described above, that is, the element size of the system monitoring reaches the best effect. The curve reflected by the size can better observe whether the metallization phase change occurs. The S parameter frequency and amplitude change are most obvious, and the sensitivity is maximum.

[0046] Specifically, the utility model discloses the material selection on DAC detection unit 3, and the metal material with the radius of 2.8cm, the height of 1.4cm is used to upper supporting block 12, lower supporting block 13. The anvil radius of upper diamond 15 and lower diamond 16 is 50 μm ~ 700 μm, and the height of anvil is 2mm ~ 5mm. The steel, tungsten, copper or rhenium metal material with the thickness of 0.2mm ~ 1.1mm is used to upper microstrip line material and lower microstrip line 9 material as high pressure DAC gasket.

[0047] Because the fluorescent line wavelength of ruby can change along with the change of the pressure, so, need to incorporate ruby powder in the sample to reach the purpose of real-time measurement of the pressure generated by diamond anvil. The specific operation steps are as follows: the ruby powder and the detection sample are placed in the sample cavity 6 together, the fluorescent spectral characteristic peak of the ruby powder is used to calibrate the measured pressure, and the sample is compacted and filled in the sample cavity 6 before the experiment. In the utility model, the lower microstrip line 9 is drilled with a micropore, which is similar to a groove structure, and the micropore is used as the sample cavity 6 for containing the sample to be measured. The installation of the detection device:

[0048] 1, the lower microstrip line 9 as high pressure DAC gasket is placed in the gap between the upper diamond 15 and the lower diamond 16, so that the gasket is tightly fixed on the two anvil tables.

[0049] 2, select the appropriate amount of sample material 17 to be measured and place it in the sample cavity 6 between the upper diamond 15 and the lower diamond 16 gasket, then, the sample material 17 is compacted. And try to fill the sample cavity 6 with the sample material 17 to be measured.

[0050] 3, slowly turn the two bolts 5 on the upper diamond 15 and cooperate with the nut, so that the upper diamond 15 and the lower diamond 16 are tightly attached while the lower microstrip antenna 9 is in the middle of the upper diamond 15 and the lower diamond 16.

[0051] The utility model adopts the mode of microstrip line and diamond anvil combination to realize the detection of the metallization transition process of the substance under high pressure, which has the advantages of simple sample structure, low power consumption, convenient and easy to use. And, the replacement of the gasket and the sample to be measured is also relatively convenient, and can be used for the research on the metallization or non-metallic transition process of high pressure science.

[0052] Metallization transition detection principle:

[0053] Before the metallization transition occurs, the lower microstrip line 9 is a metal radiation patch with micro-holes, and after the metallization transition of the substance occurs under high pressure, the lower microstrip line 9 is equivalent to a whole metal radiation patch. The radiation parameters can be measured by a vector network analyzer, and the S parameters are measured; whether the metallization transition occurs is determined by judging whether the change occurs to determine whether the substance has undergone metallization transition. Similarly, the transition of the substance from the metal state to the non-metal state under high pressure can also be detected.

[0054] The device has two parameters that can be used as detection basis:

[0055] I. S parameter amplitude. During the process of converting the sample from metal to non-metal, the S parameter value will change, so the change amount of the S parameter value at the maximum extreme value of the S parameter curve can be used to determine whether the metallization transition has occurred. The parameter amplitude difference ΔS is the difference between the transmission coefficient value S 21 before the metal transition occurs and the transmission coefficient S 21 after the metal transition occurs. The formula is ΔS = S 21 -S 21 .

[0056] II. Extreme value frequency. During the process of converting the sample from metal to non-metal, the frequency f at the maximum extreme value will also change. The parameter difference Δf is the difference between the frequency value f 21 before the metal transition occurs and the frequency value f 21 after the metal transition occurs. The formula is Δf = f 21 -f 21 .

[0057] Comparison Figure 4 , Figure 5 , Figure 6 , Figure 7 It can be found that in the utility model, when the microstrip line has a suitable size (the microstrip line width w is 2.8 mm and the difference ΔD between the upper and lower disc diameters is 4 mm), the parameter amplitude difference ΔS and the frequency difference Δf both have relatively obvious changes, so suitable S parameter difference ΔS and frequency difference Δf can be used as detection thresholds S t and f t to determine whether the metallization transition occurs. The S parameter or frequency threshold can be an experimental experience value. Under high pressure conditions, if the S parameter or frequency changes exceed the threshold, it can be determined that the metallization transition has occurred.

[0058] The above-mentioned microwave technology-based high-pressure substance metallization transition detection device is detected, and the steps are as follows:

[0059] 1. Prepare the sample to be tested and mix in the ruby powder; then place the sample to be tested in the micro-hole drilled in the center of the lower microstrip line 9, i.e. in the sample cavity 6, and make sure it is filled.

[0060] 2. Place the upper microstrip line 7 on the upper diamond 15; place the lower microstrip line 9 between the upper diamond 25 and the anvil of the lower diamond 16, with the sample cavity 6 facing the diamond anvil. Fasten the gasket part in the lower microstrip line by tightening the upper block 12 and the lower block 13 with the bolts 5 and the studs 14.

[0061] 3. Start the microwave generator 1, input the microwave signal into the port 10 of the microstrip line group in the DAC detection unit 3 through the microwave transmission line 2; the microwave signal is transmitted in the microstrip line group. The microwave signal is output from the signal output end port 8 through the microwave transmission line 2 and transmitted into the parameter detection device 4.

[0062] 4. Slowly turn the two bolts on the upper diamond 15 and cooperate with the nuts to make the upper diamond 15 tightly adhere to the lower diamond 16, and continuously increase the pressure on the sample. Observe the ruby fluorescence spectrum in the sample cavity 6 through the observation window 11 to obtain the pressure of the sample in the sample cavity 6. At the same time, measure the S parameters with the parameter detection device 4 and record the characteristic peaks or valley values (extrema) of the S parameter curve and the corresponding frequencies.

[0063] 5. According to the real-time measurement of the S parameter curve under different pressures, the S amplitude and the corresponding frequency value at the maximum extremum of the real-time S parameter curve are obtained. Compare and calculate the difference ΔS or Δf of the S parameter amplitude or frequency f at the extremum in this state and the initial state (no pressure applied, pressure is 0). The change difference ΔS or Δf of the S value and the corresponding frequency at the maximum extremum of the S parameter curve and the initial state. When the change difference ΔS or Δf reaches or exceeds the preset threshold value, it can be judged that the material has undergone a metallization transition.

[0064] Example 1

[0065] A high-pressure material metallization transition detection device based on microwave technology is composed of a microwave generator 1, a microwave transmission line 2, a DAC detection unit 3 and a parameter detection device 4. The DAC detection unit 3 adopts a four-column DAC press parameter detection mechanism.

[0066] In the four-column DAC compressor parameter detection mechanism, the upper support block 12 and the lower support block 13 are made of steel with a thickness of 1.4cm and a radius of 2.8cm, respectively. Upper diamond 15 and lower diamond 16 with an anvil radius of 100μm are selected. The lower microstrip line 9 is made of a metal material with certain toughness and ductility; in this embodiment, tungsten is used. Through simulation and solution using HFSS software on a PC, the optimal dimensions of the microstrip line are obtained as follows: total length 6.32cm, thickness 0.25mm, outer diameter of the upper microstrip line's center circle 18mm, inner diameter 2.3mm, and length of the strip-shaped portions on both sides 22.6mm and width 3.09mm; outer diameter of the lower microstrip line's center circle 14mm, inner diameter 0.46mm, and length of the strip-shaped portions on both sides 24.6mm and width 2.8mm. The most significant change is observed at the extreme value of the S-parameter curve during the metallization transition when the distance between the two microstrip lines is 1.6mm. Figure 8 As shown in the figure. During the simulation, the initial state is set to non-metallic, and the material inside the sample cavity is a non-metallic material; after the metallization transition, the material inside the sample cavity is set to a metallic material.

[0067] Depend on Figure 8 It can be seen that the maximum extreme value of the S-parameter curve during the metallization transition is in the range of 26.872 GHz to 27.214 GHz, with S-parameter and frequency changes of ΔS = 5.546 dB and Δf = 0.342 GHz, respectively. These two values ​​can be used as a reference for the detection threshold; the detection threshold S... t and f t It can be set to 5.4dB and 0.32GHz (the actual value may be slightly smaller than the simulation value), that is, when the amplitude of S decreases by about ΔS≥5.4dB, or the frequency f decreases by about Δf≥0.32GHz, the material undergoes a metallization transition.

[0068] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A microwave-based device for detecting the metalization transition of a substance under high pressure, characterized in that: The microwave generator (1), the DAC detection unit (3) and the parameter detection device (4) are connected through the microwave transmission line (2), and signal transmission is realized. The DAC detection unit (3) is mainly composed of a microstrip line group, an upper diamond (15) and a lower diamond (16). The upper diamond (15) and the lower diamond (16) are symmetrically distributed on the upper and lower sides of the microstrip line group. The DAC detection unit (3) further comprises an upper supporting block (12) and a lower supporting block (13). The upper supporting block (12) and the lower supporting block (13) are respectively located on the upper and lower sides of the upper diamond (15) and the lower diamond (16). The lower supporting block (13) is provided with a tapered observation window (11) at the bottom. The microstrip line group is composed of an upper microstrip line (7) and a lower microstrip line (9). The upper microstrip line (7) is installed on the upper diamond (15), and the middle part of the lower microstrip line (9) serves as a high-voltage DAC gasket. The center of the gasket is provided with a sample cavity (6), and the top of the upper diamond (15) is in contact with the sample cavity (6). The two sides of the microstrip line group are respectively provided with a signal input end (10) and a signal output end (8). The microwave generator (1) is connected with the signal input end (10) through the microwave transmission line (2), and the microwave signal is transmitted into the microstrip line group through the signal input end (10). The parameter detection device (4) is connected with the signal output end (8) through the microwave transmission line (2), and the microwave signal is transmitted into the parameter detection device (4) through the microwave transmission line (2) for detection.

2. The apparatus for detecting the phase transition of a substance under high pressure based on microwave technology according to claim 1, characterized in that: The upper microstrip line (7) has a hole and can be nested on the upper diamond (15).

3. The apparatus for detecting the phase transition of a substance under high pressure based on microwave technology according to claim 1, characterized in that: The middle circular part of the lower microstrip line (9) serves as a high-voltage DAC gasket, and a micro-hole is drilled in the center as a sample cavity (6) for containing the sample to be measured doped with ruby powder.

4. The apparatus for detecting the phase transition of matter under high pressure based on microwave technology according to claim 1, characterized in that: The signal input end (10) and the signal output end (8) are fixed with the microstrip line group by welding or using conductive silver glue.

5. The apparatus for detecting the phase transition of matter under high pressure based on microwave technology according to claim 1, characterized in that: The upper supporting block (12) and the lower supporting block (13) are fastened by two bolts (5) and two studs (14). Four bolt holes are symmetrically opened in the four corners of the upper supporting block (12) and the lower supporting block (13). The two bolts (5) pass through the corresponding bolt holes and are fastened with nuts to realize the support and limiting of the upper supporting block (12) and the lower supporting block (13).

6. The apparatus for detecting the phase transition of matter under high pressure based on microwave technology according to claim 1, characterized in that: The microwave generator (1) is a vector analyzer or a controllable microwave voltage-controlled oscillator (VCO). The parameter detection device (4) is a vector analyzer, a frequency meter or a detector.

7. The apparatus for detecting the phase transition of a substance under high pressure based on microwave technology according to claim 1, characterized in that: The shape of the microstrip line group is upper and lower strip lines, and a circular ring structure with unequal radius is arranged in the middle of the strip line; the upper microstrip line (7) is a circular ring, and the lower microstrip line (9) is a circular disc with a hole, the length of the two strip lines is 6cm-8cm, the width is 2mm-7mm, and the thickness is 0.2mm-1.1mm, the outer diameter of the center circle of the upper microstrip line is 15mm-25mm, and the inner diameter is 0.2mm-3.5mm, the outer diameter of the center circle of the lower microstrip line is 10mm-20mm, and the inner diameter is 0.05mm-0.7mm, the distance between the two microstrip lines is 1.5mm-3.5mm, the two ends of the microstrip line group are connected with the SMA port, and are bonded and solidified by welding or high-conductivity silver glue.

8. The apparatus for detecting the phase transition of a substance under high pressure based on microwave technology according to claim 7, characterized in that: The length of the two strip lines is 6.32cm, and the thickness is 0.25mm, the outer diameter of the center circle of the upper microstrip line is 18mm, and the inner diameter is 2.3mm, the length of the two side strip parts is 22.6mm, and the width is 3.09mm; the outer diameter of the center circle of the lower microstrip line is 14mm, and the inner diameter is 0.46mm, the length of the two side strip parts is 24.6mm, and the width is 2.8mm, and the distance between the two microstrip lines is 1.6mm.

9. The apparatus for detecting the phase transition of a substance under high pressure based on microwave technology according to claim 1, characterized in that: The upper supporting block (12) and the lower supporting block (13) are made of metal material with a radius of 2.8cm and a height of 1.4cm; the anvil surface radius of the upper diamond (15) and the lower diamond (16) is 50μm-700μm, and the anvil height is 2mm-5mm; the material of the upper microstrip line (7) and the lower microstrip line (9) used as the high-pressure DAC gasket is steel, tungsten, copper or rhenium metal material with a thickness of 0.2mm-1.1mm.

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