X-ray analysis sample holder

Abstract

The present invention relates to a sample holder for holding a sample. The sample holder includes a body having an entrance surface and an opening in the body for receiving the sample. When the sample is irradiated with x-rays, the entrance surface of the sample holder may also be irradiated, particularly at low angles of incidence. To reduce background scattering from the entrance surface, the entrance surface includes a protrusion for blocking x-rays.

Description

[Technical Field]

[0001] The present invention relates to a sample holder for supporting a sample and a method of using the sample holder in performing X-ray analysis on the sample. [Background technology]

[0002] In materials science, X-ray analysis can be used to analyze sample materials. The sample is placed in the path of an incident X-ray beam between an X-ray source and an X-ray detector. The X-ray detector is positioned to detect X-rays emitted or scattered by the sample. During analysis, the sample is contained in a sample holder.

[0003] In some types of X-ray analysis, such as X-ray diffraction (e.g., Bragg-Brentano), the sample is held in a body having a cavity. In "reflection geometry," an X-ray source irradiates the entrance face of the sample, and an X-ray detector is positioned on the same side of the entrance face as the X-ray source to detect X-rays scattered or reflected from the entrance face. In some cases, particularly when performing X-ray diffraction analysis to analyze the crystalline phase of a sample (e.g., a powder sample), it is desirable to rotate the sample during the X-ray analysis measurement.

[0004] For good results, it is important that the surface of the sample holder is very flat, allowing for accurate and precise positioning of the sample surface during the X-ray analysis measurement, which would otherwise compromise the measurement and analysis results.

[0005] X-ray analysis devices include additional components in the incident X-ray beam, the scattered X-ray beam, or both. For example, X-ray analysis devices typically include X-ray optics, beam shaping components, such as a collimator, or both. However, various components of X-ray analysis devices can cause background scattering (i.e., scattering of X-rays by things other than the sample during analysis), which can impair the results of the analysis. The sample holder is one possible source of background scattering. Background scattering from the sample holder is particularly problematic when the measurement angle is low.

[0006] It is therefore desirable to minimize sources of background scattering where possible and to take background scattering into account during analysis of results. Summary of the Invention [Means for solving the problem]

[0007] In one aspect of the present invention, there is provided a sample holder for holding a sample, the sample holder comprising: a body having a base and an entrance surface; and an opening in the body for receiving the sample, the opening extending from the entrance surface toward the base, the entrance surface having a protrusion that blocks at least a portion of X-rays incident on the entrance surface, the protrusion being formed in an area surrounding the opening. In this regard, the area between the protrusion and the entrance surface may be considered a recess, and the area of ​​the entrance surface that does not form part of the protrusion may define a floor of the recess.

[0008] The sample holder may be an X-ray diffraction sample holder. The sample may include a solid, powder, or polycrystalline sample, such as a compressed powder. Thus, the sample holder may be an X-ray diffraction polycrystalline sample holder. In this regard, the sample holder may be an X-ray diffraction powder sample holder, an X-ray diffraction compressed powder sample holder, or an X-ray diffraction solid sample holder.

[0009] The protrusion may be formed in a peripheral region of the body around the opening. The opening through which the sample is received may be in a central region of the body. Thus, the protrusion may be formed in the peripheral region of the body so as to surround the central region of the body.

[0010] In some embodiments, the sample is in the aperture and no sample is present at the entrance face of the sample holder. Because no sample is present at the entrance face of the sample holder, the entrance face is exposed to X-rays. In particular, no sample is present in the recess.

[0011] In use, X-rays from the X-ray source are directed towards the sample. X-rays diffracted by the sample are detected by the X-ray detector. Background scattering is reduced by preventing at least some of the X-rays scattered at the incident surface of the sample holder (as opposed to X-rays diffracted by the sample) from reaching the detector.

[0012] The protrusions may comprise a material that is substantially opaque to X-rays. For example, the material may absorb 90% of CuKα X-rays and transmit 10% of CuKα X-rays. The protrusions therefore prevent each X-ray incident on the protrusions from being scattered through the protrusions, thereby preventing the scattered X-rays from reaching the X-ray detector. In particular, the protrusions are positioned such that at least a portion of the X-rays that are incident on the recesses at a small angle (e.g., less than 1.5 degrees) and scattered by the recesses are blocked by the protrusions.

[0013] The entrance surface may have a plurality of protrusions and a plurality of recesses.

[0014] The protrusions and recesses are formed in the body in an area around the opening.

[0015] In some embodiments, the sample is in the aperture and the entrance face of the sample holder is free of sample, which may be exposed to X-rays from the X-ray source. In particular, no sample is present in the recess.

[0016] The protrusion and recess may each extend around the opening. The protrusion may comprise a material that is opaque to X-rays.

[0017] Each protrusion may surround an aperture and a recess may be defined between the protrusion and an adjacent protrusion, preferably the area of ​​the entrance surface between the protrusion and an adjacent protrusion forms the floor of the recess.

[0018] In a plan view of the entrance surface, each protrusion may surround an opening. Each protrusion may be continuous. Each protrusion may extend in a closed loop around the opening. Alternatively, each protrusion may surround at least 50% of the periphery of the opening (e.g., in a plan view, the protrusions may be semicircular). A recess may be defined by its floor and the opposing walls of a pair of adjacent protrusions. Adjacent protrusions may be continuous. Adjacent protrusions may be disposed next to each other without an intervening protrusion.

[0019] The plurality of protrusions may be concentric with one another.

[0020] In a plan view of the entrance surface, each of the protrusions may have the shape of an elliptical ring. Therefore, each of the protrusions may surround an aperture. Each of the protrusions may be a concentric elliptical ring.

[0021] In plan view, each protrusion may have an annular shape (in other words, each protrusion may have a circular ring shape in plan view). Each protrusion may be an annular, concentric protrusion. Each concentric protrusion may be centered on the opening.

[0022] Each of the plurality of protrusions may be elongated and tapered. Each of the plurality of recesses may be elongated and tapered.

[0023] Each protrusion extends along a length (e.g., a periphery). The protrusion may be tapered when viewed in a cross section perpendicular to the direction of extension of the protrusion. For example, each protrusion may extend around an opening to define an elliptical ring in plan view. In this case, the protrusion is tapered when viewed in a cross section perpendicular to the tangent of the elliptical ring.

[0024] The recesses may extend along a length (e.g., a periphery). The recesses may be tapered when viewed in a cross section perpendicular to the direction in which the recesses extend. For example, each recess may extend around the opening and define an elliptical ring in plan view. In this case, the recesses may be tapered when viewed in a cross section perpendicular to the tangent of the elliptical ring.

[0025] Each of the protrusions may be tapered linearly or may be tapered to an apex.

[0026] For each convex portion and its adjacent concave portion, the ratio of the height h of the convex portion to the width w of the concave portion is at least 0.001 and is equal to or less than 1.

[0027] The height of a protrusion is the maximum dimension of the protrusion in the direction of the plane of the sample holder. If there are recesses between the protrusions, the height is the difference between the highest point on the protrusion and the lowest point on the recess.

[0028] The width of a recess is the maximum distance between adjacent (consecutive) protrusions in a direction perpendicular to the height and perpendicular to the direction in which the recess extends. When viewed from a cross section perpendicular to the direction in which the recess extends, the width is the maximum distance between protrusions in a direction perpendicular to the height. If the recess is circular, the width is in a direction perpendicular to the tangent direction.

[0029] An adjacent recess is a recess immediately adjacent to a protrusion. A protrusion may have adjacent recesses on both sides.

[0030] A height to width ratio of at least 0.001 can reduce background scattering at angles 2θ less than 0.23 degrees.

[0031] Preferably, the height-to-width ratio is at least 0.01. Therefore, X-rays that strike the floor of the recess at an angle of incidence less than 1.1 degrees and are reflected will be blocked by the adjacent protrusion (located between the recess and the sample). The height-to-width ratio is preferably less than about 0.1. In this way, the incidence surface is adjusted to minimize background scattering at small angles of incidence. Furthermore, a small height-to-width ratio makes the sample holder easier to clean.

[0032] The incident surface may have a first region having a plurality of convex portions and a plurality of concave portions, and a second region having a plurality of convex portions and a plurality of concave portions, the first region and the second region being separated from each other by a separating concave portion, and the separating concave portion may have a width greater than the width of each of the concave portions in the first region and the second region.

[0033] The width of the separation recess is the maximum distance between the convex portion in the first region adjacent to the separation recess and the convex portion in the second region adjacent to the separation recess, and is the maximum distance in a direction perpendicular to the height of the convex portion and perpendicular to the direction in which the separation recess extends.

[0034] When the protrusions and / or recesses are circular or elliptical, the protrusions and / or recesses extend in the circumferential direction. The width of a recess or protrusion refers to the maximum radial dimension of the recess or protrusion. When viewed from a cross section perpendicular to the direction in which the separating recesses extend, the width refers to the maximum distance between the protrusions in the direction perpendicular to the height.

[0035] The width of the recess separating the first and second regions may be at least twice the width of the recess in the first and second regions, or at least five times the width of the recess in the first and second regions.

[0036] The height to width ratio of the isolation recess may be equal to the height to width ratio of the recess in the first region or the second region or both. By providing a relatively wide isolation recess between the first and second regions, fewer protrusions / recesses need to be formed. This therefore allows the sample holder to be manufactured relatively quickly. Furthermore, by providing a relatively wide isolation recess, the number of protrusion tips is reduced, which minimizes background scattering.

[0037] The protrusions and recesses may define a pattern with approximate circular symmetry.

[0038] In a plan view of the incidence surface, the convex portions, the concave portions, or both may define a pattern with approximately circular symmetry. The concentric circular convex portions and concave portions are circularly symmetric. Therefore, the sample holder can be conveniently used in X-ray analysis applications where the sample is rotated during measurement. For example, in X-ray diffraction analysis of a powder sample, the sample is typically rotated 360 degrees at each incidence angle.

[0039] The sample holder may further comprise a recess, which may be spiral-shaped, and the ratio of the height h of the protrusion to the width w of the recess at least 0.001 and may be less than 1. In this embodiment, the recess is spiral-shaped in a plan view of the entrance surface. The spiral defined by the protrusion and the recess (in a plan view) is approximately circularly symmetric. Preferably, the ratio of the height to the width is at least 0.01 and less than 1. More preferably, the ratio of the height to the width is less than 0.5 or less than 0.1. Most preferably, the ratio of the height to the width is at least 0.01 and less than 0.1. The protrusion may be tapered. The protrusion may extend around the opening, preferably in a spiral shape (in a plan view). The protrusion may be tapered when viewed from a cross section perpendicular to the direction in which the protrusion extends.

[0040] The opening may extend through the body, and the sample holder may further include a sample holder base that cooperates with the body and the opening to define a cavity for receiving the sample, such that the sample can be received by the sample holder within the cavity defined between the sidewall of the body that defines the opening and the sample holder base.

[0041] The body of the sample holder may be made of metal. Providing a metal body can make the sample holder easier to detect. For example, an X-ray analysis device (e.g., an X-ray diffraction device) may be equipped with an inductive proximity sensor that can detect a metal target (in this case, the sample holder) during use. It is therefore possible to determine whether the sample holder is correctly positioned to perform an X-ray analysis measurement in a convenient manner. This can help ensure that the sample is correctly aligned, or trigger the device to automatically perform a measurement, or both. Providing a metal body makes the sample holder durable and able to withstand potential wear caused by frequent rotation. Furthermore, the sample holder has a longer lifespan and can withstand frequent cleaning.

[0042] According to another aspect of the present invention, there is provided an X-ray diffraction apparatus comprising: a sample stage for supporting the sample; the sample holder described above; an X-ray source positioned to irradiate the sample with incident X-rays; an X-ray detector positioned to detect X-rays diffracted by the sample; may also be provided.

[0043] The sample stage may be configured to rotate the sample holder about a central axis perpendicular to the plane of the sample holder, thereby rotating the sample. Preferably, the X-ray source and X-ray detector are mounted on a goniometer.

[0044] According to another aspect of the present invention, there is provided a method for performing X-ray analysis of a sample, comprising the steps of: Providing a sample holder, The sample holder is a body having an entrance surface and a base; an aperture in the incident plane for receiving the sample; Equipped with the aperture extends from the entrance surface toward the base; the incidence surface has a convex portion that blocks at least a portion of the incident X-rays; including the steps The method further comprises: Inserting a sample into an opening in a sample holder; irradiating the sample and an area surrounding the sample with a plurality of X-rays such that the protrusion and the opening are irradiated; The X-ray incident angle is less than 1.5 degrees. A method is provided that includes:

[0045] Preferably, the method includes a step of irradiating the sample with X-rays at an incident angle of 1 degree or less. The sample is placed only within the aperture, and no sample is hidden on the incident surface, so that the incident surface is exposed to the incident X-rays. Therefore, there is no sample in the recess. The incident surface may have multiple recesses and multiple protrusions. The sample holder may be different from that described above. The sample may be a powder, and the method may include a step of rotating the sample. The surface of the sample irradiated with X-rays is flush with a reference plane on which the top surfaces of the protrusions are located. With this technique, the reference plane can be used as a reference for the position of the incident surface of the sample.

[0046] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0047] [Figure 1] 1 is a schematic diagram of a sample holder known in the art. [Figure 2] 1 shows a schematic diagram of a sample holder with one protrusion and one recess in a perspective view according to an embodiment of the present invention. [Figure 3]10 shows a schematic diagram in plan view of a sample holder with multiple protrusions and recesses in accordance with another embodiment of the present invention; [Figure 4] FIG. 4 is a schematic diagram of the sample holder of FIG. 3 in cross section. [Figure 5] FIG. 10 is a schematic diagram in cross section of a sample holder according to another embodiment of the present invention. [Figure 6] 1 shows a schematic diagram of a portion of a sample holder according to another embodiment of the present invention in perspective view; [Figure 7] 1 is a schematic diagram of an X-ray analysis apparatus according to an embodiment of the present invention. [Figure 8] 1 illustrates a method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0048] It should be noted that these figures are schematic and are not drawn to scale: some relative dimensions and proportions of these figures have been exaggerated or reduced for clarity and convenience in the drawings.

[0049] Referring first to FIG. 1 , a schematic diagram of a sample holder 100 known in the art for holding a powder sample is shown. The sample holder 100 comprises a base 300 and a body 500. The body 500 is an annular steel plate. One major surface of the plate forms the body base 600, and the other major surface forms the entrance surface 110. An aperture 700 extends through the center of the plate from the entrance surface 110 of the body 500 toward the base 600. The aperture 700 is located at the center of the body, and the entrance surface 110 surrounds the aperture. The sample holder body 500 and base 300 are connected such that the sample holder base 300, together with the sidewalls that define the aperture 700, form a cavity for holding the sample.

[0050] During use, a sample is inserted into the aperture 700 so that the sample's surface is aligned with the entrance face 110 of the sample holder 100. An incident X-ray beam is directed toward the sample, irradiating the sample's surface with X-rays. If the size and shape of the incident X-ray beam do not closely match the size and shape of the aperture 700, the surface of the body 500 surrounding the aperture 700 may also be illuminated by the X-rays. Thus, the incident X-ray beam may illuminate at least a portion of the entrance face 110 of the body 500. This can result in unwanted "background scattering" (i.e., scattering associated with sources other than the sample being measured) and can impair the accuracy of the X-ray analysis results. The inventors recognized that this is particularly noticeable at small angles of incidence (e.g., less than 1.5 degrees) because a larger area of ​​the sample holder is illuminated by the X-rays at small angles. Furthermore, at small angles of incidence, the X-ray signal scattered or diffracted from the sample holder is stronger.

[0051] Figure 2 shows a sample holder 1 for holding a powder sample in one embodiment of the present invention, which minimizes the "background scattering" that can be associated with the known sample holder 100 shown in Figure 1, even though many of the basic features of each sample holder are similar.

[0052] For example, and referring now to FIG. 2 , sample holder 1 similarly includes a base 3 and a body 5. Body 5 similarly is an annular steel plate. Again, one major surface of the plate forms the body base 6, and the other major surface forms the entrance surface 11. An aperture 7 extends through the center of the plate in a direction from the entrance surface 110 of body 5 toward base 6. Aperture 7 is at the center of the body, and entrance surface 11 surrounds the aperture. Sample holder body 5 and base 3 are connected such that sample holder base 3, together with sidewalls that define aperture 7, form a cavity for holding a sample.

[0053] The primary difference between the sample holder 1 shown in FIG. 2 and the sample holder 100 shown in FIG. 1 is that the entrance surface 11 of the body 5 has protrusions 13 and recesses 9 that extend around the aperture 7. The protrusions 13 extend along a path that defines a spiral in plan view, with the spiral centered at the aperture. The protrusions spiral inward from the periphery of the entrance surface 11 toward and around the aperture 7. The pattern features of the surface 11 surrounding the aperture 7 (i.e., the presence of protrusions and recesses) help reduce or avoid unwanted background scattering, as will be explained in more detail later in this specification.

[0054] During use of the sample holder 1 of FIG. 2, a sample is inserted into the opening 7 in a manner similar to that described in connection with FIG. 1. However, unlike the prior art sample holder 100 described in FIG. 1, the surface of the sample is flush with the top of the protrusion 13 of the sample holder 1 (which winds around the opening 7). An incident X-ray beam is directed toward the sample, and the X-rays irradiate the surface of the sample. In this case, even if the size and shape of the incident X-ray beam do not strictly match the size and shape of the opening 7, and even if the X-rays also irradiate the surface of the body 5 surrounding the opening 7, the protrusion 13 blocks at least a portion of the incident X-rays at the recess 9 and the entrance surface 11. The ability to block scattered and diffracted X-rays not associated with the sample itself (i.e., X-rays scattered or diffracted by the sample holder) is particularly significant at small angles of incidence (e.g., less than 1.5 degrees), where more X-rays strike the sample holder and are scattered or diffracted by it, and therefore contribute more significantly to unwanted "background scatter." The ability to block X-ray signals scattered or diffracted from the sample holder at small angles of incidence is also particularly advantageous, since the X-ray signals scattered or diffracted from the sample holder are stronger at small angles of incidence.

[0055] The recess 9 also has a spiral shape (as seen in plan view). The opposite portion of the protrusion 13 defines the recess 9. As shown in FIG. 2, the top of the protrusion 13 is substantially flat. In plan view, the pattern formed by the recess and protrusion is approximately circularly symmetric. Although there is only one protrusion or recess, due to the nature of the spiral, when the sample holder is viewed in cross section, this protrusion or recess may appear as multiple protrusions and recesses surrounding the opening 7.

[0056] In some embodiments, the recess 9 is formed by creating a spiral groove in the body 13. Thus, the body 5 and the protrusion 13 may be integrally formed.

[0057] In a preferred embodiment, the ratio of the height of the protrusions 13 to the width of the recesses 9 is greater than about 0.001 and less than about 0.1. In this way, at least a portion of the low-angle X-rays incident on the sample holder 1 are prevented from being scattered by the sample holder towards the detector.

[0058] 3 shows in plan view another embodiment of the sample holder 10. The sample holder 10 has the same structure as the sample holder in FIG. 2, except that the incident surface has a number of circular recesses and a number of circular protrusions. The recessed portions 29 and the protruding portions 23 extend around the opening 27. In this embodiment, the protruding portions 23 are concentric rings (shown as white rings) centered on the opening 27. The recessed portions 29 are concentric rings (shown as dark rings) and are defined between adjacent protruding portions 23. Therefore, as shown in FIG. 3, the entrance surface is circularly symmetric.

[0059] The width of the recesses 29 refers to the dimension extending radially between successive protrusions 23, as seen in a cross section across the diameter of the entrance face. This width is perpendicular to the direction in which the protrusions extend from the body. Each recess has the same width as the other recesses, and each protrusion has the same width as the other protrusions. Furthermore, the width of each recess and each protrusion is uniform along its respective extent; that is, the width is the same at each point around the annulus. The width of each recess 29 is greater than the width of each protrusion 23. The width of a protrusion refers to the maximum radial dimension between successive recesses.

[0060] Figure 4 shows the sample holder 10 of Figure 3 in cross section (in a plane perpendicular to the plan view of Figure 3), which is in a plane perpendicular to the tangential direction (i.e., the tangential direction of the protrusions and recesses).

[0061] The sample holder base 21 is a plate having an annular protrusion 20 around its periphery. The base 26 of the body 25 has an annular locating slot 22 that cooperates with the annular protrusion 20 in the base 21 of the sample holder 10 to mate the body 25 and base 21. An opening 27 extends through the body 25. Thus, each sidewall of the opening 27 in the body 25 and the portion of the sample holder base 23 below the opening 27 define a cavity 24 for receiving the sample.

[0062] Each protrusion 23 has an outer sidewall and an inner sidewall. The inner sidewall is on the same side of the protrusion as the opening. The outer sidewall is on the opposite side of the protrusion from the opening. The outer sidewall extends around the maximum circumference of the annulus, and the inner sidewall extends around the minimum circumference of the annulus. The top of the protrusion 23 extends between the two sidewalls. Each recess 29 is defined between adjacent protrusions 23. That is, the recess is defined between the inner sidewall of a first protrusion 23 and the outer sidewall of a neighboring (second) protrusion 23, which is positioned radially closer to the opening 27 than the first protrusion. At the bottom of the recess, a recess floor 28 extends between the outer and inner sidewalls. The top of the recess is open and flush with the top of the protrusion.

[0063] Each protrusion has a height and a width. The height of a protrusion 23 is the maximum dimension of the protrusion in the direction in which the protrusion protrudes from the main body 25. The width of a protrusion is the maximum dimension of the protrusion in the radial direction. The depth of a recess is equal to the height of the protrusions on either side of the recess. The width of a recess 29 is the distance between adjacent protrusions in the radial direction in a plane perpendicular to the tangential direction.

[0064] The width of the recesses is in the range of 10 μm to 10 mm. The height of the protrusions is in the range of 0.5 μm to 1 mm. The width of the protrusions is less than 0.5 mm. The ratio of the height of the protrusions to the width of the recesses is at least 0.001, preferably at least 0.01. The ratio of the height of the protrusions to the width of the recesses is preferably less than 1, more preferably less than about 0.1.

[0065] By arranging a protrusion and an adjacent recess such that the ratio of height to width is greater than about 0.001 and less than about 0.1, at least a portion of the low-angle x-rays incident on the sample holder are prevented from being scattered by the sample holder toward the detector.

[0066] As noted, in a preferred embodiment, the ratio of the height (h) of a protrusion to the width (w) of the recess for both the protrusion and its adjacent recess is at least 0.01. This helps reduce background scattering in measurements made at 2θ angles of approximately 2.3 degrees or less (in a Bragg-Brentano (symmetric) geometry). Background scattering over this range is particularly problematic, as it is particularly difficult to avoid irradiating the sample holder at such small angles. By way of example, each protrusion has a height of 0.05 mm and a width of 0.05 mm. Each recess has a width of 0.3 mm. Thus, the height to width ratio is approximately 0.17.

[0067] Figure 5 shows another embodiment in which the sample holder 10 of Figures 3 and 4 has tapered recesses and protrusions. As shown in Figure 5, the protrusions 231 narrow toward their tips. By providing tapered protrusions 231, the surface area at the tops of the protrusions 231 is minimized, which can help further reduce background scattering. Minimizing the surface area at the tips of the protrusions 231 minimizes the likelihood of incident X-rays 15 scattering from the tips of the protrusions 231. The recesses 29 are also tapered, with the width at the floor 28 of the recess 29 being narrower than the width at the top of the recess opposite the floor 28.

[0068] In embodiments in which the protrusions 231 taper to an apex, the width of the recess 29 refers to the distance from the tip of one protrusion to the tip of the next (i.e., adjacent) protrusion. The width of the recess can be between 10 μm and 10 mm. The height of the protrusions can be between 0.5 μm and 1 mm, and the width of the protrusions can be less than 0.5 mm. The ratio between the height of the protrusions and the width of the adjacent recess is at least 0.01. The ratio between the height of the protrusions and the width of the adjacent recess is preferably less than about 0.1.

[0069] By arranging the protrusions and their adjacent recesses so that the ratio of height to width is greater than about 0.001 and less than about 0.1, at least some of the X-rays incident at small angles can be prevented from scattering from the sample holder toward the detector.

[0070] In a preferred embodiment, the ratio of the height (h) of a protrusion to the width (w) of an adjacent recess is at least 0.01. This helps reduce background scattering in measurements made at 2θ angles of about 2.3 degrees or less (in a Bragg-Brentano (symmetric) geometry). Background scattering over this range is particularly problematic, as it is particularly difficult to avoid irradiating the sample holder at such small angles. Providing protrusions with a specific height-to-width ratio can block a large portion of the scattered and diffracted X-rays associated with the sample holder from passing through to the X-ray detector, meaning that X-ray signal transmission from the sample holder is significantly reduced (e.g., to a virtually undetectable level).

[0071] As shown in Figure 5, during use, incident X-rays 15 irradiate a sample (not shown) and sample holder 10. Some of the incident X-rays 15 are reflected by floors 28 of recesses 29 and may be detected along with X-rays from the sample. Meanwhile, protrusions 231 formed between the recesses block some of the incident X-rays. Furthermore, some of the X-rays reflected by floors 28 of recesses 29 are blocked by protrusions 231.

[0072] FIG. 6 shows a cross-sectional view of another embodiment of a sample holder 30 (only the body 35 is shown, not the base of the sample holder). The sample holder is annular (in plan view) and has an opening 37 extending completely through the body 35. A locating slot 42 is formed in the base of the sample holder. In this embodiment, the entrance surface of the sample holder 30 has five regions. Three of these regions (regions 1 through 3) have recesses and protrusions that are the same size as the recesses and protrusions in the other regions. Regions 1 through 3 occupy approximately 40 percent of the entrance surface. Region 1 31 is the region adjacent to the opening 37. Region 33 34 extends around the periphery of the body 35. Region 2 32 is located between regions 1 and 3. Regions 1 and 32 are separated by region 4 34, which consists of only a single recess. The fifth region 36 is located between the second region 32 and the third region 33, and also has only one recess. The recess in the fourth region 34 has a width greater than the widths of the recesses in the first to third regions and the fifth region. The recess in the fifth region has a width greater than the widths of the recesses in the first to third regions. Meanwhile, the ratio of height to width of each recess in the fourth and fifth regions is the same as the ratio of height to width of the protrusions and recesses in the first and second regions.

[0073] In FIG. 6, the depth of the recessed portion refers to the maximum dimension of the recessed portion in a direction perpendicular to the radial direction, as viewed in a cross section perpendicular to the tangential direction.

[0074] FIG. 7 shows an X-ray analysis apparatus 50 according to one embodiment of the present invention. The X-ray analysis apparatus is arranged in a reflection geometry. The X-ray analysis apparatus includes an X-ray tube 52 arranged to irradiate a sample 2 (e.g., a powder sample). The sample 2 is contained in a sample holder 10, which is supported by a sample stage 55. The sample is loaded into the cavity of the sample holder 1 so that the tips of each protrusion (not shown in FIG. 7 for simplicity) are in the same plane as the incidence surface of the sample 2. In this way, the tips of each protrusion are in the reference plane of the incidence surface of the sample 2. An X-ray detector 57 is arranged to receive X-rays diffracted by the sample 2.

[0075] In embodiments in which the pattern of recesses and protrusions on the entrance surface of the sample holder 1 is circularly symmetric, the sample stage is configured to rotate the sample holder 1 about a central axis that is perpendicular to the entrance surface of the sample (and that passes through both opposing major surfaces of the sample holder). In particular, the sample stage may include roller bearings that are positioned above the sample holder and configured to contact the entrance surface or the edge of the sample holder 1 at spaced locations around the periphery of the sample holder 1. The sample stage rotates the sample holder about the central axis by a motor that is positioned below the sample holder. The entrance surface rotates in a fixed plane, but the roller bearings guide the entrance surface while defining this fixed plane.

[0076] FIG. 8 illustrates a method of using a sample holder according to an embodiment of the present invention. The sample holder includes a body having an opening for receiving a sample, the opening extending from its entrance surface toward the base of the body. The entrance surface includes at least one protrusion. In a first step 60, a sample holder is provided. In an insertion step 62, a sample 2 is inserted into the opening of the sample holder 1. The sample 2 is filled into the cavity so that the entrance surface of the sample is flush with a reference surface where the tip of the protrusion is located. Using this approach, the reference surface can be used as a reference for the position of the entrance surface of the sample 2. The sample is inserted only within the opening; no sample is present on the surface surrounding the opening and having both recesses and protrusions.

[0077] In a subsequent step, a sample holder is placed on the sample stage. In some embodiments, the sample holder is made of metal and the X-ray device includes a sensor (e.g., an inductive proximity sensor) that can be used to detect the presence or absence of the sample holder.

[0078] In the irradiation step 64, the X-ray sample is irradiated with X-rays over a range of incidence angles θ having angles less than 1.5 degrees. An X-ray detector is positioned at a detection angle 2θ to receive X-rays diffracted by the powder sample. At each incidence angle θ, the sample stage may rotate the sample holder around a central axis. In this way, X-ray diffraction can be detected at various rotation angles of the sample.

[0079] It will be understood by those skilled in the art that the sample holder does not have to be circular or ring-shaped (in plan view). The shape in plan view may be elliptical or any other shape. Furthermore, the opening does not have to be circular in plan view. The opening may be elliptical or any other shape.

[0080] The sample holder may have multiple discrete protrusions arranged in a spiral rather than a single protrusion.

[0081] The protrusion and recess extend around the opening.

[0082] Although only four protrusions are shown in Figures 3-5, the sample holder can have any number of protrusions, for example, more than 20 or more than 100.

[0083] Although only three recesses are shown in Figures 3-5, the sample holder can have any number of recesses, for example more than 20 or more than 100.

[0084] In embodiments, the recesses may be formed by providing a rough surface, such as by sandblasting. However, it has been found that a sample holder with helical protrusions, concentric elliptical protrusions, or concentric circular protrusions achieves better suppression of background scattering while also achieving acceptable durability. It is desirable that the pattern is resistant to wear after prolonged rotation of a roller bearing that rotates the sample holder by directly contacting the surface of the sample holder body.

[0085] In a circularly symmetric holder (such as concentric circular grooves) or a nearly circularly symmetric holder (such as one or more spiral grooves), the one or more recesses and / or one or more protrusions may have a uniform cross-section in a plane perpendicular to the extent of the recess / protrusion (such as a plane perpendicular to the tangent direction).

[0086] If the sample holder includes multiple recesses, the recesses may have the same width as each other, or at least one of the multiple recesses may have a width different from another of the multiple recesses. Similarly, each protrusion may have the same width as the other protrusions, or at least one of the multiple protrusions may have a width different from another of the multiple protrusions.

[0087] The or each of the protrusions may have a uniform width. Each of the protrusions may have the same uniform width. The or each of the protrusions may have a uniform height. The protrusions may have the same uniform height.

[0088] The or each recess may have a uniform width.

[0089] The height of each protrusion is equal to the depth of the recess defined between that protrusion and its adjacent protrusion.

[0090] The recess(es) may be symmetrical or asymmetrical in cross section in a plane perpendicular to the extent of the recess(es).

[0091] The protrusion or protrusions may be symmetrical or asymmetrical in cross section in a plane perpendicular to the extent of the protrusion or protrusions.

[0092] The walls of each protrusion may be straight or curved in cross section in a plane perpendicular to the extent of the protrusion or protrusions.

[0093] The slope of the wall of the convex portion may be less than 30 degrees or may be less than 10 degrees.

[0094] The distance from the outer edge of a protrusion to the corresponding outer edge of the next protrusion (ie, the pitch or period of the pattern defined by the protrusions) is at least 10 μm, and preferably at least 300 μm.

[0095] The floor of the recess may be flat.

[0096] Each protrusion may taper to an apex, or the tip of each protrusion may be truncated. Each protrusion may taper to a point in a cross section in a plane perpendicular to the extent of the protrusion or protrusions (e.g., each protrusion may have an inverted V shape). Alternatively, each protrusion may be truncated. For example, in cross section, the protrusion may have the shape of a triangular pyramid truncated.

[0097] The recesses may or may not be "elongated" (for example, the recesses may be pyramidal or conical).

[0098] Each protrusion is elongated. The elongated protrusions may be linear (e.g., linear, chevron, zigzag) or curvilinear (e.g., elliptical in plan view). The linear protrusions may define a pattern, such as a honeycomb pattern.

[0099] Furthermore, the sample holder does not have to be made of steel. The sample holder may be any material that is substantially opaque to X-rays. For example, the sample holder may comprise brass.

[0100] The sample holder does not necessarily have a base separate from the body. In some embodiments, the opening may extend partway through the body to form a cavity for receiving the sample. In some other embodiments, the opening extends entirely through the body, with the cavity being defined by the opening and a surface that the sample holder contacts. For example, the cavity may be defined by a sidewall of the body that defines the opening and a surface of the sample stage.

[0101] The openings do not have to extend completely through the body of the sample holder, and in some embodiments, the openings may extend partway through the body of the sample holder, thereby avoiding the need to couple the sample holder to a base.

[0102] The body may be coated, such as with a nickel coating.

[0103] The base of the body may have an annular locating slot and the base of the sample holder may have an annular protrusion, which cooperate to mate the body of the sample holder with the base of the sample holder, but the body and base may be connected in different ways.

[0104] The sample holder may comprise a metallic body and the X-ray device may comprise a magnetic, optical or other type of sensor capable of detecting the metallic body.

Claims

1. A sample holder (1) for holding a sample (2), a body (5) having a base (6) and an entrance surface (11); an opening (7) in the body for receiving the sample, the opening extending from the entrance face towards the base; Equipped with the incident surface has a convex portion (13) that blocks at least a portion of the X-rays incident on the incident surface; the protrusion is formed in a region surrounding the opening, The protrusion (13) extends in a closed loop around the opening (7). Sample holder.

2. 2. A sample holder (1) according to claim 1, The incident surface (11) has a plurality of convex portions (13) and a plurality of concave portions (9). Sample holder.

3. A sample holder (1) according to claim 2, Each of the protrusions (13) surrounds the opening (7), A recess is defined between each protrusion and its adjacent protrusion. Sample holder.

4. A sample holder (1) according to claim 2 or 3, The plurality of protrusions are concentric with each other. Sample holder.

5. A sample holder (1) according to any one of claims 2 to 4, Each of the plurality of protrusions (13) is elongated and tapered. Sample holder.

6. A sample holder (1) according to any one of claims 2 to 5, For each convex portion (13) and its adjacent concave portion (9), the ratio of the height h of the convex portion (13) to the width w of the concave portion (9) is at least 0.001 and is equal to or less than 1; Sample holder.

7. A sample holder (1) according to any one of claims 2 to 6, The entrance surface (11) is a first region (31) having a plurality of convex portions (13) and a plurality of concave portions (9); a second region (32) having a plurality of convex portions (13) and a plurality of concave portions (9); and the first and second regions are separated from each other by a separating recess (34); The separation recess (34) has a width greater than the width of each of the recesses in the first region and the second region. Sample holder.

8. A sample holder (1) according to any one of claims 2 to 7, The protrusions (13) and recesses (9) define a substantially circularly symmetric pattern. Sample holder.

9. A sample holder (1) for holding a sample (2), a body (5) having a base (6) and an entrance surface (11); an opening (7) in the body for receiving the sample, the opening extending from the entrance face towards the base; Equipped with the incident surface has a convex portion (13) that blocks at least a portion of the X-rays incident on the incident surface; the protrusion is formed in a region surrounding the opening, the sample holder further comprises a recess; The recess has a spiral shape, a ratio of a height h of the convex portion to a width w of the concave portion is at least 0.001 and is smaller than 1; Sample holder.

10. A sample holder (1) according to claim 9, The convex portion (13) is tapered. Sample holder.

11. A sample holder (1) according to any one of claims 1 to 10, The opening (7) extends through the body (5); The sample holder further comprises a sample holder base (3), The sample holder base cooperates with the body (5) and the opening (7) to define a cavity (24) for receiving the sample (2). Sample holder.

12. A sample holder (1) according to any one of claims 1 to 11, the body (5) of the sample holder is made of metal; Sample holder.

13. A sample holder (1) according to any one of claims 2 to 7, Each of said projections (13) extends in a closed loop around said opening (7); Sample holder.

14. An X-ray diffraction apparatus (50), a sample stage (55) for supporting the sample (2); A sample holder (10) according to any one of claims 1 to 13, an X-ray source (52) arranged to irradiate the sample with incident X-rays; an X-ray detector (57) arranged to detect X-rays diffracted by the sample; An X-ray diffraction apparatus comprising:

15. 1. A method for performing X-ray analysis of a sample, comprising: Providing (60) a sample holder, The sample holder comprises: a body having an entrance surface and a base; an aperture in the entrance surface for receiving the sample; Equipped with the aperture extends from the entrance surface toward the base; the incidence surface has a convex portion that blocks at least a portion of the incident X-rays; Step (60), The method further comprises: Inserting (62) the sample into the opening of the sample holder; irradiating the sample and an area surrounding the sample with a plurality of X-rays such that the protrusion and the opening are irradiated (64); The angle of incidence of the X-rays is less than 1.5 degrees. Step (64) and Including, The sample holder (10) is a sample holder according to any one of claims 1 to 13. method.

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