In-situ measurement assembly and measurement method

Abstract

The present invention discloses an in-situ measurement assembly and measurement method. A first air diaphragm is used to increase the pressure of a diamond anvil, and a second air diaphragm is used in conjunction with a pusher to relieve the pressure. The assembly features a simple structure, low manufacturing cost, and ease of use. Furthermore, a cooling tube and a heating ring are used in conjunction with the first and second air diaphragms to provide the diamond anvil with a sample chamber pressure environment in which the pressure is increased to 300 GPa and relieved to 0, and a temperature environment in which the temperature is increased to 1000 K and cooled to 80 K. High-pressure measurement and observation are achieved by installing quartz glass windows in the upper and lower axial apertures, and electrical measurement, resistance heating, and temperature measurement at low temperatures and high pressures are achieved through flange electrodes.

Description

Technical Field

[0001] The present invention relates to the technical field of diamond anvil cell low-temperature and high-pressure in-situ measurement, and in particular to an in-situ measurement assembly and a measurement method. Background Art

[0002] Diamond anvil cell (DAC) experimental technology, a static high-pressure experimental technique for achieving ultra-high pressure, has a wide range of applications in physics, geology, materials science, and chemistry. With the high degree of cross-integration of many scientific fields, DAC technology is being widely studied in remote pressure control.

[0003] In recent years, the continuous development of remote pressure loading technologies such as air diaphragms and piezoelectric ceramics has made it possible to remotely load the DAC cavity pressure at room temperature. However, at low temperatures, the high-pressure gas inside the air diaphragm will cause it to undergo plastic deformation. When the internal gas pressure is reduced, the air diaphragm cannot return to its initial state, resulting in the DAC cavity pressure remaining high. This also makes it difficult to achieve pressure unloading through the rebound of the air diaphragm at low temperatures. In addition, in order to achieve DAC boosting and depressurization at variable temperatures (high and low temperatures) while performing high-voltage in-situ electrical and spectroscopic measurements, there are also difficulties such as difficulty in cooling due to the size of the DAC, frost on the low-temperature cold head, and insufficient working distance of the objective lens. Summary of the Invention

[0004] In view of the above problems, the present invention is proposed to provide an in-situ measurement assembly and a measurement method that overcome the above problems or at least partially solve the above problems.

[0005] In a first aspect, an in-situ measurement assembly is provided, comprising: a first assembly body, a second assembly body, and a third assembly body;

[0006] The first assembly includes a cover plate, a jacket, and a quartz plate. Two quartz plates are respectively mounted at two axial ends of the jacket. The cover plate is disposed outside the quartz plates and connected to the jacket to form a sealed cavity. The side wall of the jacket is provided with a plurality of radial through holes for connecting external devices.

[0007] The second assembly is arranged in the sealed cavity and includes a first air film cover and a second air film cover; the first air film cover and the second air film cover are connected by a connector and the distance between them is adjustable to form a compression cavity;

[0008] The third assembly is arranged in the pressing cavity, and includes a sleeve upper die, a piston lower die, a heating ring, a cooling pipe, a first air film, a tray, a support, a push table, and a second air film;

[0009] The sleeve upper die is slidably connected to the piston lower die to form a pressure chamber, and a diamond anvil is installed in the pressure chamber;

[0010] The heating ring is arranged on the periphery of the diamond anvil, and two wires of the heating ring are led out from the side surface of the sleeve upper mold to the through hole;

[0011] The cooling pipe is spirally wound around the outside of the sleeve upper mold and the piston lower mold; the inlet end and the outlet end of the cooling pipe are led out to the through hole; the first air film is arranged between the sleeve upper mold and the first air film sleeve, and the conduit of the first air film is led out to the through hole;

[0012] The tray, support seat, push platform, and second air film are arranged between the piston lower mold and the second air film sleeve; wherein, the tray is fixedly connected to the piston lower mold; one end of the support seat is connected to the tray to form a height-adjustable pressure relief chamber, and the other end abuts against the second air film sleeve; the push platform is arranged in the pressure relief chamber; a push column is provided on the push platform, and the push column passes through the tray and the flange on the side of the piston lower mold in sequence and then abuts against the end of the sleeve upper mold; the second air film is arranged between the push platform and the support seat, and the conduit of the second air film is led out to the through hole.

[0013] Optionally, the external device includes a first vacuum pump, a flange electrode, a cooling medium source, a second vacuum pump, and an air source; the first vacuum pump is sealed and connected to the through hole;

[0014] The flange electrode is sealed and connected to the through hole of the wire leading out of the heating ring;

[0015] The cooling medium source is sealedly connected to the through hole leading out of the inlet end of the cooling pipe;

[0016] The second vacuum pump is sealedly connected to the through hole leading out of the outlet end of the cooling pipe;

[0017] The air source is sealedly connected to the through holes of the conduit leading out of the first air film sheet and the conduit leading out of the second air film sheet respectively.

[0018] Optionally, the flange electrode is connected to an external heating device, a temperature measuring device or a high-voltage in-situ electrical measuring device.

[0019] Optionally, an axial opening is provided on the cover plate, and the cover plate abuts against the quartz plate through the plate wall of the axial opening and is sealed with the outer sleeve, and sealing rings are respectively provided between the quartz plate and the cover plate and the outer sleeve.

[0020] Optionally, the third assembly further includes a pad, and the two pads are respectively arranged between the sleeve upper die, the piston lower die and the two diamond anvils of the diamond anvil.

[0021] Optionally, the first air film sleeve and the second air film sleeve are connected by long screws and the spacing is adjustable, and several of the long screws pass through the first air film sleeve and the second air film sleeve in sequence and are connected to nuts; the nuts are rotated to adjust the distance between the first air film sleeve and the second air film sleeve to axially clamp the third assembly.

[0022] Optionally, the tray is fixedly connected to the piston lower mold by screws.

[0023] Optionally, an external thread is provided on the outer side of the tray, and the bracket is threadably connected to the tray via an internal thread adapted to the external thread to form a pressure relief chamber, and the bracket is rotated to adjust the distance between the bracket and the tray, thereby adjusting the cavity height of the pressure relief chamber.

[0024] In another aspect, a method for in-situ measurement is provided, comprising:

[0025] Loading a sample into the sample cavity of the diamond anvil cell in the in-situ measurement assembly;

[0026] Placing the in-situ measurement assembly on a measuring table of an in-situ measurement device with the cover corresponding to the second air film sleeve facing downward;

[0027] Connect the first assembly to a vacuum pump through the through hole on the outer shell to evacuate the vacuum chamber;

[0028] Inflating the first air film to pressurize the sample;

[0029] A cooling medium is introduced into the cooling tube to cool the sample; or the heating ring is powered to heat the sample;

[0030] performing in-situ measurement on the sample;

[0031] After the in-situ measurement is completed, the first air film is deflated, the second air film is inflated, the push platform is lifted up, and the push column lifts up the sleeve upper mold, and the pressure relief is completed.

[0032] Optionally, inflating the first air film to pressurize the sample includes:

[0033] Inflate the first air diaphragm with a gas pressure of 0 to 210 Bar, push the upper die of the sleeve downward, and increase the pressure inside the sample chamber of the diamond anvil to 300 GPa;

[0034] The step of introducing a cooling medium into the cooling tube to cool the sample comprises:

[0035] The through hole on the outer sleeve connected to the inlet end of the cooling tube is connected to a cooling medium source, and the through hole connected to the outlet end of the cooling tube is connected to a vacuum pump. The vacuum pump is started to allow the cooling medium in the cooling medium source to flow into the cooling tube, thereby cooling the interior of the sample chamber of the diamond anvil to 300K to 80K.

[0036] The step of energizing the heating ring to increase the temperature of the sample comprises:

[0037] The interior of the flange electrode on the outer sleeve is connected to the wire of the heating ring, and the exterior of the flange electrode is connected to a DC power supply. The interior of the sample chamber of the diamond anvil is heated to 1000K by adjusting the current.

[0038] The technical solution of the present invention has the following technical effects:

[0039] The diamond anvil is pressurized by the first air film, and depressurized by the second air film in conjunction with the push table and the push column. The structure is simple, the manufacturing cost is low, and it is easy to use. The cooling tube cooperates with the first air film and the second air film to provide the diamond anvil with a pressure environment in the sample chamber that can be pressurized to 300GPa and depressurized to 0, as well as a temperature environment that can be heated to 1000K and cooled to 80K, thereby realizing the pressurization and depressurization of the diamond anvil at different temperatures, and simultaneously performing high-voltage in-situ electrical and spectroscopic measurements. The observation of high-voltage measurements is achieved by installing an observation window in the middle of the cover plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0041] Figure 1 A three-dimensional diagram of an in-situ measurement assembly in an embodiment of the present invention;

[0042] Figure 2 For the second assembly Figure 1 ;

[0043] Figure 3 For the second assembly Figure 2 ;

[0044] Figure 4 A cross-sectional view of an in-situ measurement assembly according to an embodiment of the present invention;

[0045] Figure 5 Schematic diagram of the sleeve upper die;

[0046] Figure 6 Schematic diagram of the piston lower die;

[0047] Figure 7 This is a schematic diagram of the heating ring installation;

[0048] Figure 8 It is a schematic diagram of the push table;

[0049] Figure 9 A schematic diagram of a pallet;

[0050] Figure 10 A schematic diagram of the bracket;

[0051] Figure 11 This is a graph showing the relationship between temperature and time during cooling in an embodiment of the present invention;

[0052] Figure 12 1 is a graph showing the relationship between temperature and time during heating in an embodiment of the present invention. DETAILED DESCRIPTION

[0053] Exemplary embodiments of the present disclosure will be described below in more detail with reference to the accompanying drawings.

[0054] The accompanying drawings illustrate various schematic diagrams of structures according to embodiments of the present disclosure. These figures are not drawn to scale, and for the purpose of clarity, certain details are exaggerated and certain details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.

[0055] In the context of this disclosure, when a layer / element is referred to as being "on" another layer / element, the layer / element may be directly on the other layer / element or an intervening layer / element may exist therebetween. Additionally, if a layer / element is "on" another layer / element in one orientation, the layer / element may be "below" the other layer / element when the orientation is reversed. In the context of this disclosure, similar or identical components may be denoted by the same or similar reference numerals.

[0056] In order to better understand the above technical solution, the above technical solution will be described in detail below in combination with specific implementation methods. It should be understood that the embodiments of the present disclosure and the specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations on the technical solution of the present application. In the absence of conflict, the embodiments of the present application and the technical features in the embodiments can be combined with each other.

[0057] The present invention provides an in-situ measurement assembly, please refer to Figure 1 , Figure 1This is a three-dimensional diagram of the in-situ measurement assembly in an embodiment of the present invention. Figure 2 This is a cross-sectional view of an in-situ measurement assembly according to an embodiment of the present invention, comprising: a first assembly body, a second assembly body, and a third assembly body;

[0058] like Figure 1 As shown, the first assembly includes a cover plate 1, a jacket 2, and a quartz plate 3. Two quartz plates 3 are respectively installed at two axial ends of the jacket 2. The cover plate 1 is arranged outside the quartz plates 3 and connected to the jacket 2 to form a sealed cavity. The side wall of the jacket 2 is provided with a plurality of radial through holes for connecting external devices.

[0059] like Figure 2 、 3 As shown, the second assembly is arranged in the sealed cavity, including a first air film cover 4A and a second air film cover 4B; the first air film cover 4A and the second air film cover 4B are connected by a connector and the distance between them is adjustable to form a compression cavity;

[0060] like Figures 2 to 4 As shown, the third assembly is arranged in the pressing cavity, including a sleeve upper die 5, a piston lower die 6, a heating ring 7, a cooling pipe 8, a first air film 9A, a tray 10, a bracket 11, a push platform 12, and a second air film 9B;

[0061] The sleeve upper die 5 is slidably connected to the piston lower die 6 to form a pressure chamber, in which a diamond anvil 13 is installed. Figure 5 Schematic diagram of the sleeve upper die. Figure 6 Schematic diagram of the piston lower die;

[0062] like Figure 7 As shown, the heating ring 7 is arranged on the periphery of the diamond anvil 13, and two wires of the heating ring 7 are led out from the side of the sleeve upper mold 5 to the through hole;

[0063] The cooling pipe 8 is spirally wound around the outside of the sleeve upper mold 5 and the piston lower mold 6; the inlet and outlet ends of the cooling pipe 8 are led out to the through hole; the first air film sheet 9A is arranged between the sleeve upper mold 5 and the first air film sleeve 4A, and the conduit of the first air film sheet 9A is led out to the through hole;

[0064] The tray 10, the support seat 11, the push platform 12, and the second air film sheet 9B are arranged between the piston lower mold 6 and the second air film sleeve 4B; wherein, the tray 10 is fixedly connected to the piston lower mold 6; one end of the support seat 11 is connected to the tray 10 to form a height-adjustable pressure relief cavity, and the other end is in contact with the second air film sleeve 4B; the push platform 12 is arranged in the pressure relief cavity; Figure 8As shown, a push column 14 is provided on the push platform 12, and the push column 14 passes through the tray 10 and the flange on the side of the piston lower mold 6 in sequence and then abuts against the end of the sleeve upper mold 5. Figure 9 A schematic diagram of a pallet. Figure 10 Schematic diagram of the support; the second air film sheet 9B is arranged between the push platform 12 and the support 11, and the conduit of the second air film sheet 9B is led out to the through hole.

[0065] The high-pressure gas inside the first air film 9A causes it to undergo plastic deformation. When the gas pressure inside it is reduced, the air film cannot return to its original state. As a result, after the measurement is completed, the first air film 9A cannot return to its original state after being deflated. The pressure inside the diamond pressure chamber sample chamber remains high. At this time, the second air film 9B lifts the sleeve upper mold 5 to restore the first air film 9A to its original state, achieving pressure relief. During the in-situ measurement process, the first air film 9A, the second air film 9B, the cooling tube 8, and the heating ring 7 realize the in-situ measurement of the diamond anvil 13 at low and high temperatures and the rapid pressure relief after the measurement. The diamond anvil 13 here includes two diamond anvils and a sealing gasket. The sealing gasket is provided with a through hole. The anvil surfaces of the two diamond anvils are arranged on both sides of the through hole of the sealing gasket to enclose the sample chamber. The heating ring 7 is placed on the outside of the diamond anvil to heat the sample chamber.

[0066] Specifically, the external device includes a first vacuum pump, a flange electrode, a cooling medium source, a second vacuum pump, and an air source; the first vacuum pump is sealed and connected to the through-hole; the flange electrode is sealed and connected to the through-hole of the wire leading out of the heating ring 7; the cooling medium source is sealed and connected to the through-hole leading out of the inlet end of the cooling tube 8; the second vacuum pump is sealed and connected to the through-hole leading out of the outlet end of the cooling tube 8; and the air source is sealed and connected to the through-holes leading out of the conduit of the first air film 9A and the conduit of the second air film 9B, respectively. A sample is placed in the sample chamber of the diamond anvil 13, the cooling medium source pipe is connected to the through-hole on the outer sleeve 2 connected to the inlet end of the cooling tube 8 through a joint, and the vacuum pump is connected to the through-hole on the outer sleeve 2 connected to the outlet end of the cooling tube 8, so that the cooling medium can be introduced into the cooling tube 8, thereby cooling the diamond anvil 13 during the in-situ measurement process. The first air film 9A pressurizes the diamond anvil 13 during the in-situ measurement process, cooperates with the cooling tube 8 to achieve high-pressure in-situ measurement at low temperature, and cooperates with the heating ring 7 to achieve high-pressure in-situ measurement at high temperature.

[0067] Specifically, the first air film 9A and the second air film 9B are common in the industry, and have an inner diameter of 20 mm and an outer diameter of 47.5 mm. The air pressure controller is connected to an external air pressure controller through a 1.6 mm capillary tube to control the internal pressure of the air film. No limitation is imposed here.

[0068] Specifically, the cooling tube 8 can be a copper tube with an outer diameter of 4mm and a wall thickness of 1mm. It is coiled into a threaded shape that fits the sleeve upper mold 5 and the piston lower mold 6, forming a combined outer periphery. This is then wrapped around the sides of the sleeve upper mold 5 and the piston lower mold 6. The ends of the copper tube are welded to the left and rear CF internally welded pipes. The left and rear CF16 flanges are connected to CF16 flanges with internally welded 6.35mm 316L pipes. One 316L pipe is connected to a cooling medium, while the other 316L pipe is connected to a vacuum pump. The vacuum pump draws cooling medium through the copper tube to cool the entire in-situ measurement assembly, which is not a limitation here.

[0069] Specifically, the heating ring 7 is a ring-shaped high-temperature ceramic heating ring 7 with an outer diameter of 7 mm and an inner diameter of 3 mm; it is powered by a DC current source to achieve a temperature environment of 1000K, which is not limited here. In an optional embodiment, the first air film cover 4A and the second air film cover 4B are made of 316 stainless steel, processed into a pair of stainless steel sheets with an outer diameter of 80 mm, an inner diameter of 20 mm, and a thickness of 5 mm. Four holes with a diameter of 10 mm are opened at equal intervals on a circle 19 mm from the center of the stainless steel sheet; a notch with a width of 4 mm and a length of 10 mm is opened outward on a circle 10 mm from the center of the stainless steel sheet; and four holes with a diameter of 6 mm are opened at equal intervals on a circle 34 mm from the center of the stainless steel sheet, which is not limited here.

[0070] Specifically, an axial through-hole is provided on the cover plate 1, and the cover plate 1 is against the quartz plate 3 through the plate wall of the axial through-hole and is sealed with the outer sleeve 2. Sealing rings are respectively provided between the quartz plate 3 and the cover plate 1 and the outer sleeve 2. In an optional embodiment, the outer sleeve 2 is made of stainless steel 304 and processed into a cylinder with an outer diameter of 130 mm and an inner diameter of 81 mm. Quartz glass is used as an optical window at the top and bottom, and a fluororubber O-ring is used to seal the quartz and stainless steel. The quartz window can be used to achieve in-situ observation and high-pressure in-situ spectroscopic measurement. A channel with a diameter of 19 mm is opened on the side of the outer sleeve 2 and 3 standard flanges CF16 and KF16 are connected externally. The two front channels of the outer sleeve 2 are connected to the boosting and pressure relief air film pipelines, and the air film pipeline is connected to the KF16 plate with an internally welded ferrule joint. The soft telescopic bellows of KF16 are connected between the two front KF16 flanges of the outer sleeve 2 and the KF16 plate. The outer side of the KF16 plate is connected to the high-pressure air pipe to control the internal pressure of the air film.

[0071] The third assembly further includes spacers 17, two of which are disposed between the sleeve upper die 5, the piston lower die 6, and the two diamond anvils of the diamond anvil 13. The spacers 17 are used to compensate for the height difference between the diamond anvils 13 and the pressure chamber. In other words, spacers 17 of an appropriate height can be selected based on the distance between the diamond anvils and the sleeve upper die 5 and the piston lower die 6. Spacers 17 can be made of a high-hardness material such as tungsten carbide to ensure effective pressure transmission, but this is not limited here.

[0072] As an optional embodiment, the first air film sleeve 4A and the second air film sleeve 4B are connected by long screws with adjustable spacing. Several of these long screws are sequentially passed through the first air film sleeve 4A and the second air film sleeve 4B and then connected to nuts. The nuts are rotated to adjust the distance between the first air film sleeve 4A and the second air film sleeve 4B to axially clamp the third assembly. The first air film sleeve 4A and the second air film sleeve 4B are used to clamp the third assembly as a whole, providing support for the inflation and pressurization of the first air film sheet 9A and the inflation and decompression of the second air film sheet 9B.

[0073] Specifically, the tray 10 is fixedly connected to the bottom of the piston lower mold 6 by screws.

[0074] Specifically, an external thread is provided on the outside of the tray 10, and the bracket 11 is threadedly connected to the tray 10 via an internal thread that matches the external thread to form a pressure relief chamber. The bracket 11 is rotated to adjust the distance between the bracket 11 and the tray 10, thereby adjusting the height of the pressure relief chamber. The height of the pressure relief chamber is greater than the combined height of the push platform 12 and the second air film 9B, that is, the push platform 12 has a certain axial movement space in the pressure relief chamber, so that when the second air film 9B is inflated, the push platform 12 is lifted to facilitate pressure relief. As an optional embodiment, there is an axial gap of 2 to 4 mm between the push platform 12 and the tray 10, so that the push platform 12 has an axial movement space corresponding to the axial gap in the pressure relief chamber.

[0075] Specifically, the through-hole on the outer sleeve 2 connected to the inlet end of the cooling tube 8 is connected to a cooling medium source, while the through-hole connected to the outlet end of the cooling tube 8 is connected to a vacuum pump. The openings on the outer sleeve 2 can be connected to various external devices. For example, when liquid nitrogen is used as the cooling medium, a connection is required to connect to the liquid nitrogen pump. Other connections are connected to a pressure controller to control the inflation pressure of the first and second air diaphragms 9A, 9B, and thus the pressure applied to the sample chamber of the diamond anvil 13.

[0076] As an optional embodiment, the flange electrode is connected to an external heating device, a temperature measuring device or a high-voltage in-situ electrical measuring device. The flange electrode can be used in conjunction with corresponding external equipment to achieve heating, temperature measurement and high-voltage in-situ electrical measurement of the diamond anvil 13. For example, the through hole on the outer sleeve 2 adopts a CF16 flange port, and the flange electrode is composed of a glass-sintered vacuum airtight aviation plug and a CF16 flange. The flange electrode is connected to the CF16 flange port on the right side of the vacuum chamber through the CF16 flange, and the heating ring 7 is connected to an external power supply for heating, and cooperates with an external electrical measuring device for electrical measurement, and cooperates with a K-type thermocouple for temperature measurement.

[0077] Specifically, four cylindrical pins are evenly distributed on the main body of the push platform 12 as push pins 14 , and through holes adapted to the push pins 14 are provided on the flange edges of the tray 10 and the piston lower mold 6 .

[0078] Based on the same inventive concept, an embodiment of the present invention further provides an in-situ measurement method, comprising:

[0079] Loading the sample into the sample cavity of the diamond anvil 13 in the in-situ measurement assembly;

[0080] Place the in-situ measurement assembly on the measuring table of the in-situ measurement device with the cover plate 1 corresponding to the second air film sleeve 4B facing downward;

[0081] Connect the first assembly to a vacuum pump through the through hole on the outer sleeve 2 to evacuate the vacuum chamber;

[0082] Inflate the first air film 9A to pressurize the sample;

[0083] A cooling medium is introduced into the cooling tube 8 to cool the sample; or the heating ring 7 is powered to heat the sample;

[0084] performing in-situ measurement on the sample;

[0085] After the in-situ measurement is completed, the first air film 9A is deflated, the second air film 9B is inflated, the push platform 12 is lifted up, and the push column 14 lifts up the sleeve upper mold 5, and the pressure relief is completed.

[0086] During installation, the diamond anvil 13 containing the sample is installed between the sleeve upper mold 5 and the piston lower mold 6, and the first air film sheet 9A is installed on the sleeve upper mold 5; the tray 10 is installed on the piston lower mold 6, and the push platform 12 and the second air film sheet 9B are installed, and then the chassis and the tray 10 are connected; the cooling tube 8 is put on the outside of the assembled sleeve upper mold 5 and the piston lower mold 6 and placed between the two stainless steel sheets (i.e., the first air film sleeve 4A and the second air film sleeve 4B), and then four M6 screws are passed through the 6mm hole 34mm away from the center of the stainless steel sheet and connected with the nut for fixation to complete the connection between the second assembly and the third assembly, and finally the outer jacket 2 is installed, and the two ends of the cooling tube 8 are fixedly connected to the through holes on the outer jacket 2 to achieve overall fixation, and the assembly is completed after the two cover plates 1 are connected to the two ends of the sleeve.

[0087] In an optional embodiment, the method of inflating the first air film 9A to pressurize the sample includes: inflating the first air film 9A to a gas pressure of 0 to 210 Bar, pushing the sleeve upper mold 5 downward to pressurize the interior of the sample chamber of the diamond anvil 13 to 300 GPa. The method of introducing a cooling medium into the cooling tube 8 to cool the sample includes: connecting a through hole on the outer sleeve 2 connected to the inlet end of the cooling tube 8 to a cooling medium source, connecting a through hole connected to the outlet end of the cooling tube 8 to a vacuum pump, starting the vacuum pump, and allowing the cooling medium in the cooling medium source to pass into the cooling tube 8 to cool the interior of the sample chamber of the diamond anvil 13 to 300K to 80K. The relationship between temperature change with time during cooling is shown in the figure. Figure 11 As shown. The heating ring 7 is powered to heat the sample, including: the flange electrode on the outer shell 2 is connected to the wire of the heating ring 7, the flange electrode is externally connected to a DC power supply, and the temperature inside the sample chamber of the diamond anvil 13 is raised to 1000K by adjusting the current. The relationship between temperature and time during heating is shown in the figure. Figure 12 As shown. The temperature inside the sample chamber of the diamond anvil 13 is varied within the range of 1000K to 80K. Specifically, a pressure controller is used to inflate the first air film 9A with a gas pressure of 0 to 210 Bar, pushing the sleeve upper mold 5 downward to achieve pressurization inside the DAC cavity. The pressure increase and reduction rate can be adjusted according to experimental needs, and the maximum pressure increase rate can reach TPa / s (taking the diamond anvil 13 with a 50μm table as an example, the highest pressure achieved by the air film pressurization experiment is 300GPa).

[0088] This assembly is suitable for most standard models of diamond anvils 13 (diameter ~ 48mm). The anvil needs to be cooled as a whole, and the average cooling rate using copper tube conduction is about 3.67~7℃ / min. Since the cold source currently used is liquid nitrogen, the cooling range is 300K~80K. The maximum temperature of heating by energizing the heating ring 7 can reach 1000K, and the heating rate can be controlled by adjusting the power of the heating ring 7. The time of pressurization and depressurization can be set as needed. The pressure can be increased to more than 50GPa within milliseconds, or it can be increased slowly by adding 0.1GPa at a time. In addition, the pressurization and depressurization rates are different for anvils with different anvil surface sizes (500μm\300μm\100μm\50μm).

[0089] The technical solution provided in the embodiment of the present invention has at least the following technical effects or advantages: the diamond anvil is pressurized by the first air film, and the diamond anvil is depressurized by the second air film in cooperation with the push table and the push column, with a simple structure, low manufacturing cost and easy use; the diamond anvil is provided with a pressure environment in which the pressure in the sample chamber is increased to 300GPa and depressurized to 0, and the temperature is changed to a range of 1000K to 80K by the cooling tube in cooperation with the first air film and the second air film, thereby realizing the pressurization and depressurization of the diamond anvil under variable temperature conditions, and simultaneously performing high-voltage in-situ electrical and spectroscopic measurements, and realizing observation of high-voltage measurements by installing an observation window in the middle of the cover plate.

[0090] In the description provided herein, numerous specific details are described. However, it is understood that embodiments of the present invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0091] Similarly, it should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the claims below, inventive aspects lie in less than all the features of the individual embodiments disclosed above. Accordingly, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of the invention.

[0092] It should be noted that the above embodiments illustrate rather than limit the invention, and that a person skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between brackets should not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The present invention may be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third etc. does not indicate any order. These words may be interpreted as names.

Claims

1. An in-situ measurement assembly, characterized in that: include: The first assembly, the second assembly, and the third assembly; The first assembly includes a cover plate, a jacket, and a quartz plate. Two quartz plates are respectively mounted at two axial ends of the jacket. The cover plate is disposed outside the quartz plates and connected to the jacket to form a sealed cavity. The side wall of the jacket is provided with a plurality of radial through holes for connecting external devices. The second assembly is arranged in the sealed cavity and includes a first air film cover and a second air film cover; the first air film cover and the second air film cover are connected by a connector and the distance between them is adjustable to form a compression cavity; The third assembly is arranged in the compression cavity, including a sleeve upper die, a piston lower die, a heating ring, a cooling tube, a first air film, a tray, a bracket, a push table, and a second air film; wherein, the first air film sleeve and the second air film sleeve are connected by long screws and the spacing is adjustable, and a plurality of the long screws pass through the first air film sleeve and the second air film sleeve in sequence and are connected to nuts; the nuts are turned to adjust the distance between the first air film sleeve and the second air film sleeve to axially clamp the third assembly; The sleeve upper die is slidably connected to the piston lower die to form a pressure chamber, and a diamond anvil is installed in the pressure chamber; The heating ring is arranged on the periphery of the diamond anvil, and two wires of the heating ring are led out from the side surface of the sleeve upper mold to the through hole; The cooling pipe is spirally wound around the outside of the sleeve upper mold and the piston lower mold; the inlet end and the outlet end of the cooling pipe are led out to the through hole; the first air film is arranged between the sleeve upper mold and the first air film sleeve, and the conduit of the first air film is led out to the through hole; The tray, the supporting seat, the pushing platform, and the second air film are arranged between the piston lower mold and the second air film sleeve; wherein, the tray is fixedly connected to the piston lower mold; one end of the supporting seat is connected to the tray to form a height-adjustable pressure relief chamber, and the other end abuts against the second air film sleeve; the pushing platform is arranged in the pressure relief chamber; a pushing column is provided on the pushing platform, and the pushing column passes through the tray and the flange on the side of the piston lower mold in sequence and abuts against the end of the sleeve upper mold; the second air film is arranged between the pushing platform and the supporting seat, and the conduit of the second air film is led out to the through hole; The external device includes a first vacuum pump, a flange electrode, a cooling medium source, a second vacuum pump, and an air source; the first vacuum pump is sealed and connected to the through hole; The flange electrode is sealed and connected to the through hole of the wire leading out of the heating ring; The cooling medium source is sealedly connected to the through hole leading out of the inlet end of the cooling pipe; The second vacuum pump is sealedly connected to the through hole leading out of the outlet end of the cooling pipe; The air source is sealedly connected to the through holes of the conduit leading out of the first air film sheet and the conduit leading out of the second air film sheet respectively.

2. The in-situ measurement assembly according to claim 1, wherein: The flange electrode is connected to an external heating device, a temperature measuring device or a high-voltage in-situ electrical measuring device.

3. The in-situ measurement assembly according to claim 1, wherein: An axial opening is provided on the cover plate, and the cover plate abuts against the quartz plate through the plate wall of the axial opening and is sealed with the outer sleeve. Sealing rings are respectively provided between the quartz plate and the cover plate and the outer sleeve.

4. The in-situ measurement assembly according to claim 1, wherein: The third assembly further includes a pad, and two of the pads are respectively arranged between the sleeve upper die, the piston lower die and the two diamond anvils of the diamond anvil.

5. The in-situ measurement assembly according to claim 1, wherein: The tray is fixedly connected to the piston lower die by screws.

6. The in-situ measurement assembly according to claim 1, wherein: An external thread is provided on the outer side of the tray, and the bracket is threadably connected to the tray via an internal thread adapted to the external thread to form a pressure relief chamber. The bracket is rotated to adjust the distance between the bracket and the tray, thereby adjusting the cavity height of the pressure relief chamber.

7. A method for performing in-situ measurement using the in-situ measurement assembly according to any one of claims 1 to 6, characterized in that: include: Loading a sample into the sample cavity of the diamond anvil cell in the in-situ measurement assembly; Placing the in-situ measurement assembly on a measuring table of an in-situ measurement device with the cover corresponding to the second air film sleeve facing downward; Connect the first assembly to a vacuum pump through the through hole on the outer shell to evacuate the vacuum chamber; Inflating the first air film to pressurize the sample; A cooling medium is introduced into the cooling tube to cool the sample; or the heating ring is powered to heat the sample; performing in-situ measurement on the sample; After the in-situ measurement is completed, the first air film is deflated, the second air film is inflated, the push platform is lifted up, and the push column lifts up the sleeve upper mold, and the pressure relief is completed.

8. The in-situ measurement method according to claim 7, wherein: The step of inflating the first air film to pressurize the sample includes: Inflate the first air diaphragm with a gas pressure of 0 to 210 Bar, push the upper die of the sleeve downward, and increase the pressure inside the sample chamber of the diamond anvil to 300 GPa; The step of introducing a cooling medium into the cooling tube to cool the sample comprises: The through hole on the outer sleeve connected to the inlet end of the cooling tube is connected to a cooling medium source, and the through hole connected to the outlet end of the cooling tube is connected to a vacuum pump. The vacuum pump is started to allow the cooling medium in the cooling medium source to flow into the cooling tube, thereby cooling the interior of the sample chamber of the diamond anvil to 300K to 80K. The step of energizing the heating ring to increase the temperature of the sample comprises: The interior of the flange electrode on the outer sleeve is connected to the wire of the heating ring, and the exterior of the flange electrode is connected to a DC power supply. The interior of the sample chamber of the diamond anvil is heated to 1000K by adjusting the current.

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