CN219144114U - Differential pressure diaphragm and electron microscope - Google Patents

Abstract

The utility model discloses a differential pressure diaphragm and an electron microscope, wherein the differential pressure diaphragm is used for the electron microscope and comprises a diaphragm sheet and a graphene film, wherein diaphragm holes are formed in the diaphragm sheet and used for limiting gas to pass through and passing through electron beams, the graphene film is arranged on the diaphragm sheet and covers the diaphragm holes, and the graphene film is used for preventing gas from passing through and passing through the electron beams. The pressure difference diaphragm can effectively simplify the structure of the electron microscope and improve the operation convenience of the electron microscope.

Description

Differential pressure diaphragm and electron microscope

Technical Field

The utility model relates to the technical field of electron scanning microscopes, in particular to a differential pressure diaphragm and an electron microscope.

Background

An environmental scanning electron microscope (Environmental Scanning Electron Microscope, ESEM) is one type of electron scanning microscope. The method can be used for carrying out morphological observation and qualitative and quantitative element analysis on various solid and liquid samples and carrying out phase change process observation on partial solution. In an environment scanning electron microscope, a pressure difference diaphragm is arranged at the lower pole shoe of an objective lens of the environment scanning electron microscope so as to ensure the vacuum of an electron gun chamber and simultaneously allow gas to flow in a sample chamber, so that the pressure in the sample chamber can be adjusted within the range of 0.1 to 50 torr according to the requirement of electron beam operation and sample characterization on different vacuum degrees. The pressure difference diaphragm is usually formed by arranging a small hole of tens of micrometers on a diaphragm sheet made of molybdenum or platinum metal, wherein the small hole can limit air flow and can allow electron beam spots to pass through.

In the related art, when a sample in the sample chamber needs to be replaced, a bin gate of the sample chamber can be opened to facilitate the replacement of the sample, and at the moment, external gas flows into the sample chamber and enters the electron gun chamber through the pressure difference diaphragm, so that the vacuum state in the electron gun chamber is easily damaged. In order to ensure that the vacuum degree of the electron gun chamber is not affected by the replacement of the sample, a mechanical sealing structure, such as a sealing valve, is usually arranged at one end of the electron gun chamber close to the sample chamber, and the electron gun chamber is sealed by the mechanical sealing structure when the sample is replaced. However, by the arrangement, the structure of the electron microscope is complex, the manufacturing difficulty of the electron microscope is improved, the operation difficulty of the electron microscope is increased, and the operation of operators is not facilitated.

Disclosure of Invention

The embodiment of the application discloses a differential pressure diaphragm and an electron microscope, which can effectively simplify the structure of the electron microscope and improve the operation convenience of the electron microscope.

To achieve the above object, in a first aspect, an embodiment of the present application discloses a differential pressure diaphragm for an electron microscope, the differential pressure diaphragm including:

the diaphragm sheet is provided with diaphragm holes which are used for limiting the passage of gas and passing electron beams;

the graphene film is arranged on the diaphragm sheet and covers the diaphragm hole, and the graphene film is used for preventing gas from passing through and passing through electron beams.

In this embodiment, the differential diaphragm is used in an electron microscope, and the diaphragm sheet is provided with a diaphragm hole for limiting the passage of gas, so that when the differential diaphragm is installed between an electron gun chamber and a sample chamber of the electron microscope, the electron gun chamber can be maintained in a high vacuum state, and the sample chamber is maintained in a low vacuum state, and at the same time, an electron beam is allowed to pass through the diaphragm hole, so that the electron beam emitted by the electron gun can pass through the diaphragm hole to reach a sample in the sample chamber, and the electron microscope can perform morphological observation or qualitative and quantitative analysis on the sample. On this basis, set up the graphene film in the diaphragm piece, and cover the diaphragm hole, thereby the graphene film is used for preventing gas and is used for supplying electron beam to pass, namely, the diaphragm hole that covers has the graphene film can prevent gaseous passing through, only allow electron beam to pass, like this, when changing the sample in the sample room, need not additionally to set up mechanical seal structure and can prevent the outside gas entering the sample room and get into the electron gun room, electron microscope's structure has been simplified, electron microscope's preparation degree of difficulty has been reduced, simultaneously, electron microscope's operation steps have still been simplified, electron microscope's simple operation has been improved, do benefit to operating personnel's operation use.

In a possible implementation manner of the first aspect, the graphene film is attached to the surface of the diaphragm sheet, the area overlapping with the surface of the diaphragm sheet is A, and the area of the diaphragm hole is B, wherein A/B is greater than or equal to 4.

Therefore, the ratio of the area of the graphene film overlapped with the surface of the diaphragm sheet to the area of the diaphragm hole is greater than or equal to 4, so that the lamination between the graphene film and the diaphragm sheet is firm and stable, and the diaphragm sheet is not easy to damage due to different pressures at two sides of the differential pressure diaphragm.

In a possible implementation manner of the first aspect, a distance between an edge of the graphene film and a geometric center of the diaphragm hole is L, and a diameter of an circumcircle of the diaphragm hole is D, wherein L/D is equal to or greater than 2.

The ratio of the distance between the edge of the graphene film and the geometric center of the diaphragm hole to the diameter of the circumscribed circle of the diaphragm hole is greater than or equal to 2, so that the graphene film can be effectively ensured to be attached to the diaphragm sheet, and the attaching areas of the graphene film and the diaphragm sheet in any direction of the geometric center of the diaphragm hole are larger, so that the attaching of the graphene film and the diaphragm sheet is more firm and stable.

In a possible implementation manner of the first aspect, a distance between a geometric center of the graphene film and an edge of the graphene film is C, and C is 0.5 um-50 um.

The preparation process of the graphene film in the size range is mature, the preparation is easy, the area of the graphene film is not easy to occur and is larger than that of the diaphragm sheet, the situation that part of the graphene film is positioned on the outer side of the diaphragm sheet when the graphene film is attached to the diaphragm sheet is prevented, and the attachment of the graphene film and the diaphragm sheet is facilitated, and meanwhile the attachment area between the graphene film and the diaphragm sheet is also large.

In a possible implementation manner of the first aspect, the graphene film is a rectangular graphene film or a circular graphene film, and a projection of a geometric center of the rectangular graphene film or the circular graphene film on the diaphragm sheet coincides with a geometric center of the diaphragm hole.

Therefore, the shape of the graphene film is rectangular or circular, so that the shape of the graphene film is regular and symmetrical, the manufacturing is easy, the orthographic projection of the geometric center of the graphene film on the diaphragm sheet coincides with the geometric center of the diaphragm hole, the area of the graphene film, which is attached to the diaphragm sheet, is approximately the same in all directions of the graphene film around the center hole of the diaphragm hole, and when different pressures act on two sides of the graphene film, the forces born by all parts of the graphene film, which are attached to the diaphragm sheet, are approximately the same, so that the situation that the graphene film is detached from the diaphragm sheet due to the fact that the force born by one part of the graphene film is small is avoided.

In a possible implementation manner of the first aspect, the diaphragm sheet has a first face and a second face opposite to each other, and the graphene film is disposed on any one of the first face and the second face.

Through the graphene film setting on any one of two surfaces of diaphragm piece, can need not additionally to sign diaphragm piece's first face and second face in order to prevent graphene film subsides dislocation position, reduced graphene film and diaphragm piece's laminating degree of difficulty.

In a possible implementation manner of the first aspect, the graphene film is attached to the first surface or the second surface by van der waals force, compared with the graphene film attached to the diaphragm sheet by glue, the material is saved, and the attachment is more compact.

In a possible implementation manner of the first aspect, the edge portion of the graphene film is provided with a reinforcing layer, so that the firmness of bonding between the graphene film and the diaphragm sheet is further enhanced.

In a possible implementation manner of the first aspect, the reinforcing layer is any one of a carbon layer and a platinum layer, or the reinforcing layer is a metal carbide layer, and the structure is simple and easy to implement.

In a possible implementation manner of the first aspect, the diaphragm sheet is provided with a fixing hole, the fixing hole is located at the periphery of the diaphragm hole, and the fixing hole is used for connecting the diaphragm sheet with the electron microscope.

Therefore, the diaphragm sheet can be sequentially penetrated in the fixing hole and the threaded hole arranged on the electron microscope through the screw and fixed in the electron microscope, and the diaphragm sheet is easy to install and detach.

In a possible implementation manner of the first aspect, the plurality of fixing holes are formed in edges of the diaphragm sheet and are uniformly distributed around the center of the diaphragm sheet, so that the diaphragm sheet is firmly and stably fixed in the electron microscope.

In a second aspect, embodiments of the present application also disclose an electron microscope, including:

a barrel including a barrel cavity, opposite first and second ends, the barrel cavity extending through the first and second ends to form an electron gun chamber;

the electron gun is used for generating electron beams, the electron gun is arranged at the first end, and the emission end of the electron gun is accommodated in the electron gun chamber;

the diaphragm support is arranged at the second end, a vacuum channel is formed on the diaphragm support, the extending direction of the vacuum channel is the same as that of the cylinder cavity and is communicated with the cylinder cavity, the two ends of the vacuum channel are respectively provided with the differential pressure diaphragm of any one of the first aspect, and the projection of the differential pressure diaphragm along the extending direction of the vacuum channel covers the vacuum channel;

the sample chamber is arranged on one side of the diaphragm support, which is far away from the lens barrel, and is used for placing a sample.

In this embodiment, the electron gun is located at the first end of the lens barrel, the emission end of the electron gun is accommodated in the electron gun chamber, the diaphragm support is disposed at the second end of the lens barrel, and the vacuum channel of the diaphragm support is communicated with the electron gun chamber, the extending direction of the diaphragm support is also the same as that of the electron gun chamber, the sample chamber is disposed at one side of the diaphragm support, which is away from the lens barrel, so that the electron beam emitted by the electron gun can pass through the differential pressure diaphragm along the electron gun chamber and the vacuum channel to reach the surface of the sample placed in the sample chamber, and the electron microscope (such as an environmental scanning electron microscope) can observe the shape of the sample or perform qualitative and quantitative analysis on the element.

And the two ends of the vacuum channel are respectively provided with a differential pressure diaphragm, so that the flow of gas between the electron gun chamber and the sample chamber is limited, the electron gun chamber can be maintained in a high vacuum state, and the sample chamber can be maintained in a low vacuum state.

Compared with the prior art, the application has the following beneficial effects:

in the application, the differential pressure diaphragm is used in an electron microscope, the diaphragm sheet is provided with a diaphragm hole for limiting gas to pass through, so that when the differential pressure diaphragm is arranged between an electron gun chamber and a sample chamber of the electron microscope, the electron gun chamber can be kept in a high vacuum state, the sample chamber is kept in a low vacuum state, and meanwhile, electron beams are allowed to pass through, and the electron beams emitted by the electron gun can pass through the diaphragm hole to reach a sample in the sample chamber, so that the electron microscope can observe the shape of the sample or perform qualitative and quantitative analysis on the element, and the like.

On this basis, set up the graphene film in the diaphragm piece, and cover the diaphragm hole, thereby the graphene film is used for preventing gas and is used for supplying electron beam to pass, namely, the diaphragm hole that covers has the graphene film can prevent gaseous passing through, only allow electron beam to pass, like this, when changing the sample in the sample room, need not additionally to set up mechanical seal structure and can prevent the outside gas entering the sample room and get into the electron gun room, electron microscope's structure has been simplified, electron microscope's preparation degree of difficulty has been reduced, simultaneously, electron microscope's operation steps have still been simplified, electron microscope's simple operation has been improved, do benefit to operating personnel's operation use.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a front view of a first differential diaphragm provided in an embodiment of the present application;

FIG. 2 is a front view of a second pressure differential diaphragm provided in an embodiment of the present application;

FIG. 3 is a front view of a third pressure differential diaphragm provided in an embodiment of the present application;

FIG. 4 is a schematic view of a part of the structure of an electron microscope according to an embodiment of the present application;

fig. 5 is a schematic structural diagram of a diaphragm support and differential pressure diaphragm combination according to an embodiment of the present application.

Reference numerals illustrate:

1-diaphragm sheets; 11-diaphragm aperture; 12-fixing holes; 2-graphene film; 100-electron microscope; 110-a lens barrel; 120-electron gun; 1210-electron beam; 130-diaphragm support; 140-differential pressure diaphragm; 150-sample chamber; 1510—sample.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In the present utility model, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate an azimuth or a positional relationship based on that shown in the drawings. These terms are only used to better describe the present utility model and its embodiments and are not intended to limit the scope of the indicated devices, elements or components to the particular orientations or to configure and operate in the particular orientations.

Also, some of the terms described above may be used to indicate other meanings in addition to orientation or positional relationships, for example, the term "upper" may also be used to indicate some sort of attachment or connection in some cases. The specific meaning of these terms in the present utility model will be understood by those of ordinary skill in the art according to the specific circumstances.

Furthermore, the terms "mounted," "configured," "provided," "connected," and "connected" are to be construed broadly. For example, it may be a fixed connection, a removable connection, or a unitary construction; may be a mechanical connection, or an electrical connection; may be directly connected, or indirectly connected through intervening media, or may be in internal communication between two devices, elements, or components. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

Furthermore, the terms "first," "second," and the like, are used primarily to distinguish between different devices, elements, or components (the particular species and configurations may be the same or different), and are not used to indicate or imply the relative importance and number of devices, elements, or components indicated. Unless otherwise indicated, the meaning of "a plurality" is two or more.

The utility model provides a differential pressure diaphragm and an electron microscope, which can effectively simplify the structure of the electron microscope and improve the operation convenience of the electron microscope.

The technical scheme of the present application will be described in detail below with reference to specific embodiments and accompanying drawings.

Example 1

The embodiment of the application provides a differential pressure diaphragm, the differential pressure diaphragm is used for electron microscope, as shown in fig. 1 and 2, differential pressure diaphragm 140 includes diaphragm piece 1 and graphene film 2, wherein, be provided with diaphragm hole 11 on the diaphragm piece 1, diaphragm hole 11 is used for restricting gaseous passing through and is used for the electron beam to pass through, graphene film 2 sets up on diaphragm piece 1, and covers diaphragm hole 11, and graphene film 2 is used for preventing gaseous passing through and is used for the electron beam to pass through.

The diaphragm aperture 11 is used to restrict the passage of gas, and is capable of allowing a small amount of gas molecules to pass therethrough, and is not completely capable of preventing the flow of gas, and is capable of maintaining the vacuum state of the electron gun chamber and the sample chamber when the electron gun chamber is in a vacuum state and the sample chamber is in a low vacuum state.

In this embodiment, the pressure difference diaphragm 140 is used in an electron microscope, and the diaphragm sheet 1 is provided with a diaphragm hole 11 for restricting the passage of gas, so that when the pressure difference diaphragm 140 is installed between an electron gun chamber and a sample chamber of the electron microscope, the electron gun chamber can be maintained in a high vacuum state, and the sample chamber is maintained in a low vacuum state, and at the same time, the electron beam is allowed to pass through, so that the electron beam emitted by the electron gun can pass through the diaphragm hole 11 to reach the sample in the sample chamber, and the electron microscope can perform morphological observation or qualitative and quantitative analysis of elements on the sample.

Based on this, set up graphene film 2 in diaphragm piece 1, and cover diaphragm hole 11, thereby graphene film 2 is used for preventing gas and is used for supplying electron beam to pass through, namely, the diaphragm hole 11 that covers graphene film 2 can prevent gas's passing through, only allow electron beam to pass through, like this, when changing the sample in the sample room, need not to set up extra mechanical seal structure and can prevent the outside gas that gets into the sample room and get into in the electron gun room, electron microscope's structure has been simplified, electron microscope's preparation degree of difficulty has been reduced, simultaneously, electron microscope's operation steps have still been simplified, electron microscope's simple operation has been improved, do benefit to operating personnel's operation and use.

The electron microscope may be any of a transmission electron microscope, a scanning electron microscope, a reflection electron microscope, an emission electron microscope, and the like, such as an environmental scanning electron microscope, and is not limited herein.

The diaphragm sheet 1 may be a molybdenum sheet or a platinum sheet, and is not limited thereto. The aperture 11 is a small hole with a size of tens micrometers formed in the aperture sheet 1, and can limit air to pass through and allow electron beam spots to pass through. The shape of the diaphragm aperture 11 may be any of a circle, a square, an ellipse, and the like, and is not limited thereto.

When the graphene film 2 is disposed on the diaphragm sheet 1, the graphene film 2 may be one layer, two layers, or more layers, which is not limited herein.

In addition, the graphene film 2 covers the diaphragm hole 11, so that the graphene film 2 just covers the diaphragm hole 11, and materials are saved; the area of the graphene film 2 may be larger than the area of the diaphragm aperture 11, that is, after the graphene film 2 is attached to the diaphragm sheet 1, the edge of the graphene film 2 is a certain distance from the aperture edge of the diaphragm aperture 11, so that the attaching area between the graphene film 2 and the diaphragm sheet 1 is larger, and the attaching between the graphene film 2 and the diaphragm sheet 1 is firmer.

Optionally, when the area of the graphene film 2 is larger than the area of the diaphragm hole 11, and the graphene film 2 is attached to the surface of the diaphragm sheet 1, the area overlapping with the surface of the diaphragm sheet 1 is A, the area of the diaphragm hole 11 is B, and A/B is not less than 4.

Therefore, the ratio of the area of the graphene film 2 overlapped with the surface of the diaphragm sheet 1 to the area of the diaphragm hole 11 is greater than or equal to 4, so that the bonding between the graphene film 2 and the diaphragm sheet 1 is firm and stable, and the damage caused by different pressures at two sides of the differential pressure diaphragm 140 is not easy to occur.

The area of the graphene film 2 overlapping the surface of the diaphragm sheet 1 may be 4 times, 5 times, 5.5 times, 6 times, or the like the area of the diaphragm aperture 11, and is not limited thereto.

In addition, when the ratio of the overlapping area of the graphene film 2 and the diaphragm sheet 1 to the area of the diaphragm hole 11 is smaller than 4, the area of the graphene film 2 and the diaphragm sheet 1, which is attached, is smaller, the vacuum degree in the electron gun chamber on one side of the diaphragm sheet 1 is determined, the vacuum degree in the sample chamber on the other side of the diaphragm sheet 1 is in a certain range (for example, between 0.1 torr and 50 torr), and some adjustment is performed on different samples, namely, when the pressure difference on two sides of the diaphragm sheet 1 is different for different samples, at this time, if the area of the graphene film 2 and the diaphragm sheet 1, which are attached, is smaller, the pressure which can be born by the graphene film 2 attached on the diaphragm sheet 1 is smaller, and the pressure difference range between the electron gun chamber and the sample chamber is reduced, namely, the adjustment range of the vacuum degree in the sample chamber is reduced.

In addition, the ratio of the area of the graphene film 2 overlapped with the surface of the diaphragm sheet 1 to the area of the diaphragm hole 11 is greater than or equal to 4, that is, the area of the graphene film 2 is greater than the area of the diaphragm hole 11, and at the same time, the area of the graphene film 2 may be smaller than or equal to the area of the diaphragm sheet 1, so that the material of the graphene film 2 may be saved.

Alternatively, as shown in fig. 1 and 2, the distance between the edge of the graphene film 2 and the geometric center of the diaphragm hole 11 is L, and the diameter of the circumscribed circle of the diaphragm hole 11 is D, where L/D is not less than 2.

It should be noted that, the distance between the edge of the graphene film 2 and the geometric center of the diaphragm aperture 11 is L, which means that the distance between any edge of the graphene film 2 and the geometric center of the diaphragm aperture 11 can be represented by L, and is not a specific value.

Therefore, the ratio of the distance between the edge of the graphene film 2 and the geometric center of the diaphragm hole 11 to the diameter of the circumcircle of the diaphragm hole 11 is greater than or equal to 2, so that when the graphene film 2 is attached to the diaphragm sheet 1, the attaching areas of the graphene film 2 and the diaphragm sheet 1 in any direction of the geometric center of the diaphragm hole 11 are larger, and the attaching of the graphene film 2 and the diaphragm sheet 1 is firmer and more stable.

For example, when the diaphragm hole 11 is a circular hole, the diameter of the diaphragm hole 11 is the diameter D of the circumscribed circle of the diaphragm hole 11, the distance between the nearest edge of the graphene film 2 from the diaphragm hole 11 and the center of the diaphragm hole 11 may be L, and at this time, only the ratio between L and D is greater than or equal to 2, so that the ratio between any point on the edge of the graphene film 2 and the center of the diaphragm hole 11 is greater than or equal to 2, which facilitates the attachment of the graphene film 2 on the diaphragm sheet 1.

Alternatively, as shown in FIGS. 1 and 2, the distance between the geometric center of the graphene film 2 and the edge of the graphene film 2 is C,0.5 um.ltoreq.C.ltoreq.50 um.

From this, the distance between the geometric center of graphene film 2 and the edge of graphene film 2 is located between 0.5um ~ 50um, and the preparation technology of this size within range's graphene film 2 is mature, can easily make the realization, and be difficult for appearing the area of graphene film 2 and be greater than diaphragm piece 1's area, has prevented that graphene film 2 from pasting the condition that appears partial graphene film 2 to be located diaphragm piece 1's outside when locating diaphragm piece 1, has made things convenient for the laminating of graphene film 2 and diaphragm piece 1 in, can also make the laminating area between graphene film 2 and diaphragm piece 1 great.

The distance between the geometric center of the graphene film 2 and the edge of the graphene film 2 may be 1um, 10um, 20um, 40um, etc., which is not limited herein.

In addition, if the distance between the geometric center of the graphene film 2 and the edge of the graphene film 2 is less than 0.5um, the area of the graphene film 2 is less than 0.25um ² The condition that the area difference between the graphene film and the diaphragm aperture 11 is smaller easily occurs, and the attaching difficulty of the graphene film 2 and the diaphragm sheet 1 is increased.

If the distance between the geometric center of the graphene film 2 and the edge of the graphene film 2 is greater than 50um, i.e. the area of the graphene film 2 is greater than 2500um ² The size of the graphene film 2 is larger, and the manufacturing difficulty of the graphene film 2 is improved.

The graphene film 2 may be produced by any of a plurality of methods, including, but not limited to, a micro-mechanical lift-off method, a vapor phase chemical deposition method, a plasma-enhanced vapor phase chemical deposition method, and a redox method.

Alternatively, as shown in fig. 1 and 2, the graphene film 2 is a rectangular graphene film 2 or a circular graphene film 2, and the projection of the geometric center of the rectangular graphene film 2 or the circular graphene film 2 on the diaphragm sheet 1 coincides with the geometric center of the diaphragm aperture 11.

Therefore, the shape of the graphene film 2 is rectangular or circular, so that the shape of the graphene film 2 is regular and symmetrical, the manufacturing is easy, the orthographic projection of the geometric center of the graphene film 2 on the diaphragm sheet 1 coincides with the geometric center of the diaphragm hole 11, the area of the graphene film 2, which is attached to the diaphragm sheet 1 in all directions, is approximately the same around the center hole of the diaphragm hole 11, when the two sides of the graphene film 2 are acted by different pressures, the forces born by all parts of the graphene film 2, which are attached to the diaphragm sheet 1, are approximately the same, and the situation that the graphene film 2 is detached from the diaphragm sheet 1 due to the fact that the force born by one part of the graphene film 2 is small is avoided.

When the graphene film 2 is a rectangular graphene film 2, the size range of the length and width of the graphene film 2 may be between 1um and 100um, and the rectangular graphene film 2 may be a rectangular graphene film 2 or a square graphene film 2, which is not limited herein. In addition, when the graphene film 2 is a circular graphene film 2, the diameter range of the graphene film 2 may be between 1um and 100 um.

In some embodiments, the diaphragm sheet 1 has first and second faces opposite to each other, and the graphene film 2 is provided on either one of the first and second faces.

Therefore, the graphene film 2 is arranged on any one of the two surfaces of the diaphragm sheet 1, and the first surface and the second surface of the diaphragm sheet 1 can be identified without additionally attaching the graphene film 2 to the wrong position, so that the attaching process of the graphene film 2 and the diaphragm sheet 1 is simplified, and the attaching difficulty of the graphene film 2 and the diaphragm sheet 1 is reduced.

When the first surface or the second surface of the diaphragm sheet 1 to which the graphene film 2 is attached is assembled in the electron microscope, the pressure difference diaphragm 140 may be attached in a direction of the graphene film 2 toward the electron gun chamber, or the pressure difference diaphragm 140 may be attached in a direction of the graphene film 2 toward the sample chamber, which is not limited herein.

The graphene film 2 is attached to the first surface or the second surface, which can have various implementation manners, and in one possible implementation manner, the graphene film 2 is attached to the first surface or the second surface through glue.

In a second possible implementation, the graphene film 2 may be attached to the first or second face by van der waals forces.

Therefore, the graphene film 2 and the diaphragm sheet 1 can be bonded without other materials or structures, so that the materials are saved, and the bonding is more compact.

It should be noted that the van der waals force is also called intermolecular force or van der waals force, and is a weakly alkaline electrical attraction existing between neutral molecules or atoms.

In addition, after the graphene film 2 is attached to the first surface or the second surface by van der waals force, the edge portion of the graphene film 2 can be reinforced, and a reinforcing layer can be arranged at the edge portion of the graphene film 2, so that the attaching firmness of the graphene film 2 and the diaphragm sheet 1 is further enhanced.

The implementation manner of the reinforcing layer is multiple, for example, the reinforcing layer can be any one of a carbon layer or a platinum layer, or the reinforcing layer is a metal carbide layer, so that the edge of the graphene film 2 can be effectively reinforced by the above implementation manner, and the structure is simple and easy to realize.

And when the reinforcing layer is a carbon layer or a platinum layer, the carbon layer or the platinum layer can be formed on the edge part of the graphene film 2 through deposition, so that the process is mature and easy to realize.

When the reinforcing layer is a metal carbide layer, the edge part of the graphene film 2 and the diaphragm sheet 1 can be subjected to heat treatment by heat treatment processes such as vacuum high-temperature heating, laser irradiation and the like, so that the two react to form the metal carbide layer, and the process is mature and easy to realize.

Alternatively, as shown in fig. 3, the diaphragm sheet 1 is provided with a fixing hole 12, the fixing hole 12 is located at the outer periphery of the diaphragm hole 11, and the fixing hole 12 is used for connecting the diaphragm sheet 1 with an electron microscope.

Thus, by providing the fixing hole 12 in the diaphragm sheet 1, the diaphragm sheet 1 can be fixed to the electron microscope by sequentially penetrating the fixing hole 12 and the screw hole provided in the electron microscope with the screws, and the diaphragm sheet 1 can be easily attached and detached.

The fixing hole 12 is located at the outer periphery of the diaphragm hole 11, and prevents the diaphragm sheet 1 from interfering with the diaphragm hole 11 when fixed by the fixing hole 12. The fixing hole 12 may be located at the edge of the diaphragm sheet 1, or may be located in an area between the edge of the diaphragm sheet 1 and the diaphragm hole 11 on the diaphragm sheet 1, which is not limited herein.

Optionally, as shown in fig. 3, the plurality of fixing holes 12 are provided, and the plurality of fixing holes 12 are provided at the edge of the diaphragm sheet 1 and uniformly distributed around the center of the diaphragm hole 11, so that the diaphragm sheet 1 is fixed in the electron microscope while being easy to disassemble and assemble, and is also firmly and stably fixed.

The number of the fixing holes 12 may be two, three or more, which is not limited herein.

Example two

The embodiment of the present application further provides an electron microscope, as shown in fig. 4 and 5, including a lens barrel 110, an electron gun 120, a diaphragm support 130, and a sample chamber 150, wherein the lens barrel 110 includes a barrel cavity, a first end and a second end opposite to each other, and the barrel cavity penetrates through the first end and the second end to form the electron gun 120 chamber; the electron gun 120 is used for generating an electron beam 1210, the electron gun 120 is arranged at the first end, and the emitting end of the electron gun 120 is accommodated in the electron gun 120 chamber; the diaphragm support 130 is disposed at the second end, the diaphragm support 130 is formed with a vacuum channel, the extending direction of the vacuum channel is the same as the extending direction of the cylinder cavity, and is communicated with the cylinder cavity, two ends of the vacuum channel are respectively provided with the differential pressure diaphragm 140 according to any one of the first embodiment, the projection of the differential pressure diaphragm 140 along the extending direction of the vacuum channel covers the vacuum channel, the sample chamber 150 is disposed at one side of the diaphragm support 130, which is far away from the lens barrel 110, and the sample chamber 150 is used for placing the sample 1510.

In this embodiment, the electron gun 120 is located at a first end of the lens barrel 110, the emission end of the electron gun 120 is accommodated in the electron gun 120 chamber, the diaphragm support 130 is disposed at a second end of the lens barrel 110, the vacuum channel of the diaphragm support 130 is communicated with the electron gun 120 chamber, the extending direction of the diaphragm support 130 is also the same as that of the electron gun 120 chamber, and the sample chamber 150 is disposed at a side of the diaphragm support 130 facing away from the lens barrel 110, such that the electron beam 1210 emitted by the electron gun 120 can pass through the differential diaphragm 140 along the electron gun 120 chamber and the vacuum channel to reach the surface of the sample 1510 placed in the sample chamber 150, such that the electron microscope 100 can perform morphological observation or qualitative and quantitative analysis on the sample 1510.

And the two ends of the vacuum channel are respectively provided with a pressure difference diaphragm 140, which restricts the flow of gas between the electron gun 120 chamber and the sample chamber 150, so that the electron gun 120 chamber can be maintained in a high vacuum state, and the sample chamber 150 can be maintained in a low vacuum state.

In addition, since the pressure difference diaphragm 140 in the electron microscope 100 is the pressure difference diaphragm 140 in any one of the above embodiments, the pressure difference diaphragm 140 in the present embodiment has the technical effect of the pressure difference diaphragm 140 in the first embodiment, that is, when the sample 1510 in the sample chamber 150 is replaced, the outside air can be effectively prevented from entering the electron gun 120 chamber, the structure of the electron microscope 100 can be effectively simplified, and the operation convenience of the electron microscope 100 can be improved. In addition, since the technical effects of the differential diaphragm 140 have been fully described in the first embodiment, the description thereof will not be repeated here.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present utility model, and not for limiting the same; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the utility model.

Claims (11)

1. A differential pressure diaphragm for an electron microscope, the differential pressure diaphragm comprising:

the diaphragm sheet is provided with diaphragm holes which are used for limiting the passage of gas and passing electron beams;

the graphene film is arranged on the diaphragm sheet and covers the diaphragm hole, and the graphene film is used for preventing gas from passing through and passing through electron beams.

2. The differential pressure diaphragm according to claim 1, wherein the graphene film is attached to the surface of the diaphragm sheet, the area overlapping with the surface of the diaphragm sheet is A, the area of the diaphragm hole is B, and A/B is not less than 4.

3. The differential pressure diaphragm according to claim 2, wherein the distance between the edge of the graphene film and the geometric center of the diaphragm aperture is L, and the diameter of the circumcircle of the diaphragm aperture is D, L/D is equal to or greater than 2.

4. A differential pressure diaphragm according to claim 3, characterized in that the distance between the geometrical centre of the graphene film and the edges of the graphene film is C,0.5 um.ltoreq.c.ltoreq.50 um.

5. The differential pressure diaphragm of claim 1, wherein the graphene film is a rectangular graphene film or a circular graphene film, and a projection of a geometric center of the rectangular graphene film or the circular graphene film on the diaphragm sheet coincides with a geometric center of the diaphragm aperture.

6. The differential pressure diaphragm of claim 1 wherein the diaphragm sheet has first and second opposed faces, the graphene film being disposed on either of the first and second faces.

7. The differential pressure diaphragm of claim 6 wherein the graphene film conforms to the first face or the second face by van der waals forces.

8. The differential pressure diaphragm of claim 6, wherein the edge portion of the graphene film is provided with a reinforcing layer.

9. The differential pressure diaphragm of claim 8, wherein the reinforcing layer is either a carbon layer or a platinum layer, or the reinforcing layer is a metal carbide layer.

10. The differential pressure diaphragm according to any one of claims 1-9, characterized in that the diaphragm sheet is provided with fixing holes, which are located at the periphery of the diaphragm hole, for connection of the diaphragm sheet to the electron microscope.

11. An electron microscope, comprising:

a barrel including a barrel cavity, opposite first and second ends, the barrel cavity extending through the first and second ends to form an electron gun chamber;

the electron gun is used for generating electron beams, the electron gun is arranged at the first end, and the emission end of the electron gun is accommodated in the electron gun chamber;

the diaphragm support is arranged at the second end, a vacuum channel is formed on the diaphragm support, the extending direction of the vacuum channel is the same as that of the cylinder cavity and is communicated with the cylinder cavity, the two ends of the vacuum channel are respectively provided with the differential pressure diaphragm according to any one of claims 1-10, and the projection of the differential pressure diaphragm along the extending direction of the vacuum channel covers the vacuum channel;

the sample chamber is arranged on one side of the diaphragm support, which is far away from the lens barrel, and is used for placing a sample.

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