JP2012173042A - Particle orientation apparatus and particle orientation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a particle orientation apparatus in which, when orientating particles in a three-dimensional manner, orientation accuracy can be improved, and a particle orientation method.SOLUTION: A particle orientation apparatus 1 includes a magnetic field generation unit 12, a drive unit 13, and a control unit 14. The drive unit 13 revolves a sample container 2 in which particles are suspended relatively to the magnetic field generation unit 12 at a speed required for forming a revolving magnetic field. Each time the sample container 2 is revolved at 180°, the control unit 14 controls driving of the drive unit 13 to approximately temporarily stop the relative revolution for a predetermined time trequired for forming a static magnetic field.

Description

  The present invention relates to a fine particle alignment apparatus and a fine particle alignment method for three-dimensionally aligning fine particles suspended in a sample by applying a time-varying magnetic field.

X-ray structural analysis is known as a technique for analyzing the crystal structure of an object. This X-ray structural analysis is usually performed using a single crystal or microcrystalline powder of about 100 μm or more. In recent years, a method has been developed in which microcrystalline particles suspended in a sample (hereinafter simply referred to as “fine particles”) are three-dimensionally oriented and analyzed in a quasi-single crystal state.
With respect to this method, conventionally, fine particles having different magnetic susceptibility in three directions orthogonal to each other are three-dimensionally oriented, and a fine particle is obtained by applying a time-varying magnetic field to a sample in which the fine particles are suspended. There is known a fine particle aligning apparatus for three-dimensionally aligning (see, for example, Patent Documents 1 and 2 and Non-Patent Document 1).

  For example, as shown in Non-Patent Document 1, the time-varying magnetic field is a magnetic field generated on the xy plane, and the angular velocity of the sample is changed every 90 degrees around the z axis perpendicular to the xy plane. It is formed by rotating while. The angular velocity is set low in a range of 90 degrees passing through the x-axis and high in a range of 90 degrees passing through the y-axis. As a result, a static magnetic field is formed in the vicinity of the x axis where the sample rotates at a low speed, and a rotating magnetic field is formed in the vicinity of the y axis which rotates at a high speed. In the rotating magnetic field, the magnetization difficult axis of the fine particles can be oriented in the z-axis direction.

JP 2008-039699 A JP 2006-057055 A

Tsunehisa Kimura, “Control of orientation of microcrystalline powder using a strong magnetic field-Application to diffraction and spectroscopy”, Journal of the Japan Neutron Science Society, VOL17 No. 55, pp. 55-58

  In the conventional fine particle aligning apparatus, since the static magnetic field is formed while rotating the sample at a low speed over a wide range of 90 degrees, when the magnetic easy axis of the fine particles is aligned in the static magnetic field, There was a problem that the hard axis of magnetization that was oriented by the immediately preceding rotating magnetic field fluctuated and the orientation of the hard axis of magnetization was disturbed.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a fine particle aligning apparatus and a fine particle aligning method capable of improving the alignment accuracy when three-dimensionally aligning fine particles.

  The fine particle aligning device of the present invention is a fine particle aligning device that applies a time-varying magnetic field to a sample in which fine particles having different susceptibility in three directions orthogonal to each other are suspended to three-dimensionally align the fine particles. A magnetic field generation unit, a drive unit that rotates the sample relative to the magnetic field generation unit at a speed necessary to form a rotating magnetic field, and the sample is approximately 180 × n degrees (n is an arbitrary value) A control unit that drives and controls the drive unit so as to temporarily stop the relative rotation temporarily for a predetermined time required to form a static magnetic field each time it rotates relatively. It is characterized by that.

  In addition, the fine particle orientation method of the present invention is a fine particle orientation method in which a magnetic field that varies with time is applied to a sample in which fine particles having different magnetic susceptibility in three directions orthogonal to each other are suspended to three-dimensionally orient the fine particles. A method in which the sample is rotated relative to the magnetic field generator at a speed required to form a rotating magnetic field, and the sample is rotated approximately 180 × n degrees (n is an arbitrary natural number). In addition, the relative rotation is temporarily substantially stopped for a predetermined time necessary for forming the static magnetic field.

  According to the fine particle aligning apparatus and fine particle aligning method of the present invention, since a rotating magnetic field is formed by rotating a sample in which fine particles are suspended relative to a magnetic field generating unit by a driving unit, it is difficult to magnetize the fine particles. The axis can be oriented in a direction perpendicular to the rotating field surface. In addition, since the static magnetic field is formed by temporarily stopping the relative rotation of the sample temporarily, the easy magnetization axis of the fine particles can be oriented so as to be parallel to the static magnetic field surface. At that time, since the relative rotation is substantially stopped locally at a rotation position of about 180 × n degrees, the static magnetic field is less than that in the case where the sample is rotated at a low speed over a wide range of 90 degrees as in the prior art. The time to be formed can be shortened. Thereby, it is possible to prevent the orientation of the hard magnetization axis from being disturbed while orienting the easy magnetization axis of the fine particles, and therefore it is possible to increase the alignment accuracy when the fine particles are three-dimensionally oriented.

In addition, it is preferable that the control unit drives and controls the drive unit so as to temporarily stop the relative rotation temporarily every time the sample rotates 180 degrees.
In this case, since the relative rotation is substantially stopped every time the sample rotates 180 degrees, the time for which the rotating magnetic field is formed can be shortened compared to the case where the sample rotates 360 degrees or more. Thereby, it is possible to prevent the orientation of the easy magnetization axis from being disturbed while orienting the hard magnetization axis of the fine particles, so that the alignment accuracy when the fine particles are three-dimensionally oriented can be further increased.

Further, it is preferable that when the relative rotation is substantially stopped, the control unit drives and controls the drive unit so as to completely stop the relative rotation.
In this case, since the relative rotation is completely stopped, a stable static magnetic field can be formed. Thereby, since the orientation of the easy axis of the fine particles can be accurately performed, the alignment accuracy when the fine particles are three-dimensionally oriented can be further increased.

Moreover, it is preferable that the predetermined time for relatively rotating the sample is set so as to satisfy the relationship of the following equation.
_tr <δ ² / D ₁
Here, t _r is the time for relatively rotating the sample, [delta] is the permissible maximum half-width of the diffraction spot needed for X-ray structure analysis, D ₁ is the rotational diffusion coefficient around the axis of easy magnetization.
In this case, the alignment accuracy when the fine particles are three-dimensionally aligned can be further increased.

Further, it is preferable that the predetermined time for substantially stopping the relative rotation of the sample is set so as to satisfy the relationship of the following equation.
t _s <δ ² / D ₃
Here, t _s is a predetermined time to substantially stop the relative rotation of the sample, [delta] is the permissible maximum half-width of the diffraction spot needed for X-ray structure analysis, D ₃ is the rotational diffusion coefficient of around hard axis.
In this case, the alignment accuracy when the fine particles are three-dimensionally aligned can be further increased.

Moreover, it is preferable that the time for relatively rotating the sample and the predetermined time for substantially stopping the relative rotation of the sample are set so as to satisfy the relationship of the following formula.
_{t r / t s = 2 (} χ1-χ2) / (χ3-χ2)
Here, t _r is the time for relatively rotating the sample, t _s is a predetermined time to substantially stop the relative rotation of the sample, .chi.1 the magnetic susceptibility of the easy magnetization axis, chi-square magnetization of the intermediate shaft, Kai3 the magnetization hard axis Magnetic susceptibility (where χ1>χ2> χ3).
In this case, the alignment accuracy when the fine particles are three-dimensionally aligned can be further increased.

Moreover, it is preferable that the relative rotational speed of the sample is set so as to satisfy the relationship of the following formula.
ωq × 6ημ ₀ / (B ² (χ1-χ2)) >> 1/2
Where ωq is the angular velocity at which the sample rotates relatively, η is the viscosity coefficient of the suspension, μ ₀ is the permeability of vacuum, B is the magnetic field strength, χ 1 is the susceptibility of the easy axis, and χ 2 is the susceptibility of the intermediate axis. (Where χ1> χ2).
In this case, the orientation accuracy of the easy axis can be further increased.

  Moreover, it is preferable that the said drive part is what rotates the said sample. In this case, since the sample is rotated, the entire apparatus can be made compact as compared with the case where the magnetic field generator is rotated.

  The driving unit is preferably a stepping motor. In this case, drive control of the drive unit by the control unit can be easily performed by using a stepping motor.

  According to the present invention, it is possible to prevent the orientation of the hard magnetization axis from being disturbed while orienting the easy magnetization axis of the fine particles. Therefore, it is possible to improve the alignment accuracy when the fine particles are three-dimensionally oriented.

1 is a side view showing a schematic configuration of a fine particle orientation device according to a first embodiment of the present invention. It is a perspective view which shows the magnetization axis | shaft of microparticles | fine-particles. It is a schematic diagram which shows the control method of the drive part by a control part. It is a perspective view explaining the three-dimensional orientation of microparticles | fine-particles. It is a schematic diagram which shows the control method of the drive part by the control part of the fine particle aligning apparatus which concerns on the 2nd Embodiment of this invention. It is a table | surface which shows the half value width of the peak obtained by the X-ray diffraction of the sample quasi-single-crystallized by the fine particle orientation device of this invention. FIG. 7 is a drawing-substituting photograph showing an X-ray diffraction image of a sample quasi-single-crystallized under Condition B in FIG. 6. FIG. 7 is a drawing-substituting photograph showing an X-ray diffraction image of a sample quasi-single-crystallized under Condition D in FIG. 6. It is a side view which shows schematic structure of the fine particle aligning apparatus which concerns on the 3rd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a side view showing a schematic configuration of a fine particle orientation device according to a first embodiment of the present invention. The fine particle orientation device 1 applies a time-varying magnetic field (hereinafter referred to as a time-varying magnetic field) to the sample container 2 disposed at a predetermined position. The sample container 2 contains a sample in which fine particles 3 (see FIG. 2) such as an organic compound, an inorganic compound, or a biological material in a pharmaceutical field, a biotechnology field, a polymer material field, etc. are suspended. .

  The fine particles 3 are made of biaxial crystals having different susceptibility in three directions orthogonal to each other, and magnetically have biaxial anisotropy. FIG. 2 is a perspective view showing the magnetization axis of the fine particles 3. As shown in FIG. 2, the fine particle 3 has three different magnetic susceptibility χ1, χ2, and χ3 in each of the three axial directions, and has a magnitude relationship of χ1> χ2> χ3. Hereinafter, the axis of the magnetic susceptibility χ1 is called an easy axis, the axis of the magnetic susceptibility χ2 is called an intermediate axis, and the axis of the magnetic susceptibility χ3 is called a hard axis.

  The fine particle orientation device 1 includes a casing 11, a magnetic field generation unit 12 disposed in the casing 11, a drive unit 13 that rotates the sample container 2 with respect to the magnetic field generation unit 12, and drives the drive unit 13. And a control unit 14 for controlling.

  The magnetic field generator 12 includes a pair of upper and lower permanent magnets 12 a and 12 b fixed to the casing 11. Each permanent magnet 12a, 12b is formed in a spherical shape, and is disposed such that the north and south poles face each other. A space S for arranging the sample container 2 is formed between the permanent magnets 12a and 12b.

The drive unit 13 is composed of, for example, a stepping motor, and a chuck 15 that holds the sample container 2 is attached to the tip of the rotating shaft 13a. Thus, when the drive unit 13 is driven, the sample container 2 rotates with respect to the fixed magnetic field generation unit 12 via the rotation shaft 13a and the chuck 15. At that time, the rotation speed of the sample container 2 is set to a speed necessary for forming a rotating magnetic field. More specifically, the rotation speed of the sample container 2 is set so as to satisfy the relationship of the following formula.
ωq × 6ημ ₀ / (B ² (χ1-χ2)) >> 1/2 (1)
Here, ωq is the angular velocity at which the sample container 2 rotates, η is the viscosity coefficient of the suspension, μ ₀ is the vacuum permeability, and B is the magnetic field strength.

Control unit 14, 180 × n degrees sample container 2 is substantially (n is an arbitrary natural number) to each rotation of a predetermined period of time t _s required for forming a static magnetic field, temporarily substantially stops its rotation The drive unit 13 is controlled to be driven. At that time, the sample container 2, over the predetermined time t _r, and rotates approximately 180 × n degrees. Here, “substantially stopped” means not only a state in which it is completely stopped but also a state in which it is slowly rotating locally so that a static magnetic field is substantially formed.

The predetermined time t _r for rotating the sample pipe 2 and the predetermined time t _s for substantially stopping the rotation of the sample pipe 2 are set so as to satisfy the following expressions (2), (3), and (4), respectively. Has been.
_tr <δ ² / D ₁ (2)
t _s <δ ² / D ₃ (3)
_{t r / t s = 2 (} χ1-χ2) / (χ3-χ2) ··· (4)
Here, δ is an allowable maximum half width of the diffraction spot necessary for the X-ray structure analysis, D ₁ is a rotational diffusion coefficient around the easy magnetization axis, and D ₃ is a rotational diffusion coefficient around the hard magnetization axis.

  FIG. 3 is a schematic diagram illustrating a method for controlling the drive unit 13 by the control unit 14. In the present embodiment, as shown in FIG. 3, a time-varying magnetic field is applied on the xy plane by the control unit 14. Hereinafter, for example, a case where the sample container 2 is rotated clockwise around the z axis with the x axis above the z axis as a reference (0 degree) will be described. The x-axis is arranged in parallel with the magnetic field direction indicated by the arrow B.

First, the sample container 2 is rotated at a predetermined angular velocity ωq (preferably 60 rpm) in a 180-degree range (rotation angle αq) including the y-axis from the 0-degree position to the 180-degree position. At the position of 180 degrees on the x axis, the sample container 2 is completely stopped for a predetermined time t _s (preferably 1 second).

Thereafter, in the range of 180 degrees (rotation angle αq) including the y-axis from the position of 180 degrees to the position of 0 degrees (360 degrees), the sample container 2 is rotated again by the angular velocity ωq. Then, the sample container 2 is completely stopped for a predetermined time t _s (preferably 1 second) on the x-axis which is the 0 degree position. Thus, the time-varying magnetic field is applied by controlling the drive unit 13 so that the rotation is temporarily stopped every time the sample container 2 rotates 180 degrees.

  When the time-varying magnetic field is applied in this way, the fine particles 3 suspended in the sample container 2 are formed with a rotating magnetic field during rotation, so that the hard axis of magnetization of the fine particles 3 is the xy plane (rotation surface). Oriented in the z-axis direction perpendicular to. Then, by forming a static magnetic field during the stop, the easy axis of magnetization of the fine particles 3 is oriented in the x-axis direction arranged parallel to the magnetic field direction B, and the remaining axes are automatically in the y-axis direction. Oriented. As a result, the microparticles 3 change from a randomly arranged state as shown in FIG. 4A to a three-dimensionally oriented state as shown in FIG. 4B, that is, a quasi-single crystal state. In this state, X-ray structure analysis can be performed by irradiating the sample container 2 with X-rays a from the X-ray source (not shown) in the direction perpendicular to the paper surface of FIG.

  As described above, according to the fine particle alignment apparatus and the fine particle alignment method of the present embodiment, the rotating magnetic field is formed by rotating the sample container 2 in which the fine particles 3 are suspended with respect to the magnetic field generating unit 12. Can be oriented in a direction perpendicular to the rotating magnetic field plane. Further, since the static magnetic field is formed by temporarily stopping the rotation of the sample container 2, the easy magnetization axis of the fine particles 3 can be oriented so as to be parallel to the static magnetic field surface. At that time, since the rotation of the sample container 2 is substantially stopped locally at a rotation position of about 180 × n degrees, the sample container 2 is more static than the conventional case where the sample is rotated at a low speed over a wide range of 90 degrees. The time for forming the magnetic field can be shortened. Thereby, it is possible to prevent the orientation of the hard magnetization axis from being disturbed while the easy magnetization axis of the fine particles 3 is being oriented, so that the orientation accuracy when the fine particles 3 are three-dimensionally oriented can be increased.

  Further, since the control unit 14 drives and controls the drive unit 13 so as to temporarily stop the rotation of the sample container 2 every time the sample container 2 rotates 180 degrees, it is compared with the case where the sample container 2 rotates 360 degrees or more. Thus, the time for forming the rotating magnetic field can be shortened. Thereby, it is possible to prevent the orientation of the easy magnetization axis from being disturbed while orienting the hard magnetization axis of the fine particles 3, so that the alignment accuracy when the fine particles 3 are three-dimensionally oriented can be further increased. .

  Moreover, since the control part 14 drive-controls the drive part 13 so that rotation of the sample container 2 may be stopped completely, it can form the stable static magnetic field. Thereby, since the orientation of the easy axis of the fine particles 3 can be accurately performed, the alignment accuracy when the fine particles 3 are three-dimensionally oriented can be further increased.

Further, the predetermined time t _s to substantially stop the relative rotation of the predetermined time t _r and the sample container 2 for relatively rotating the sample container 2, each of the above formulas (2), so as to satisfy the relation (3) and (4) Since it is set, the alignment accuracy when the fine particles 3 are three-dimensionally aligned can be further increased. In particular, when Expression (4) is satisfied, it is effective in that the half widths of the diffraction spots of the easy magnetization axis, the intermediate axis, and the hard magnetization axis can be made equal.

  Moreover, since the rotation speed of the sample container 2 is set so as to satisfy the relationship of the above formula (1), the orientation accuracy of the easy axis of the fine particles 3 can be further increased.

Further, since the driving unit 13 rotates the sample container 2, the entire apparatus can be made compact as compared with the case where the magnetic field generating unit 12 is rotated.
In addition, since a stepping motor is used as the drive unit 13 that rotates the sample container 2, drive control of the drive unit 13 by the control unit 14 can be easily performed.

  FIG. 5 is a schematic diagram showing a control method of the drive unit 13 by the control unit 14 of the fine particle orientation device according to the second embodiment of the present invention. The fine particle orientation device of the present embodiment is different from the first embodiment in that the sample container 2 is brought into a substantially stopped state by slowly rotating the sample container 2 locally without being completely stopped.

  In FIG. 5, for example, the case where the sample container 2 is rotated in the clockwise direction with reference to the x-axis above the z-axis will be described. The range of 170 degrees including the y-axis from the position of 5 degrees to the position of 175 degrees. At (rotation angle αq), the sample container 2 is rotated at a high speed at a predetermined angular velocity ωq (preferably 60 rpm). In a range of 10 degrees including the x-axis from the position of 175 degrees to the position of 185 degrees (rotation angle αs), the sample container 2 is rotated at a low speed at a predetermined angular velocity ωs (preferably 10 rpm) and is substantially stopped. And

  Thereafter, in the range of 170 degrees including the y axis from the position of 185 degrees to the position of 355 degrees (rotation angle αq), the sample container 2 is rotated at a high speed by the angular velocity ωq, and further 5 degrees (365 degrees from the position of 355 degrees) In the range of 10 degrees (rotation angle αs) including the x-axis up to the position (degrees), the sample container 2 is rotated at a low speed by the angular velocity ωs to be in a substantially stopped state. In this way, a time-varying magnetic field is applied by drivingly controlling the drive unit 13 by the control unit 14 so as to temporarily rotate (substantially stop) each time the sample container 2 rotates at a high speed of 170 degrees. .

  When the time-varying magnetic field is applied in this way, the fine particles 3 suspended in the sample container 2 are formed with a rotating magnetic field during high-speed rotation, so that the hard magnetization axis of the fine particles 3 is the xy plane (rotation surface). ) In the z-axis direction perpendicular to. Then, by forming a static magnetic field during low-speed rotation, the easy axis of magnetization of the fine particles 3 is oriented in the x-axis direction arranged in parallel with the magnetic field direction B, and the remaining axes are automatically in the y-axis direction. Oriented. As a result, the microparticles 3 change from a randomly arranged state as shown in FIG. 4A to a three-dimensionally oriented state as shown in FIG. 4B, that is, a quasi-single crystal state. In this state, X-ray structure analysis can be performed by irradiating the sample container 2 with X-rays a from the X-ray source (not shown) in the direction perpendicular to the paper surface of FIG.

  As described above, also in the fine particle aligning apparatus and the fine particle aligning method of the present embodiment, the sample container 2 is rotated slowly and locally in a substantially stopped state, so that the magnetic field generating unit 32 extends over a wide range of 90 degrees as in the past. Thus, the time for forming the static magnetic field can be shortened as compared with the case of rotating at low speed. Thereby, it is possible to prevent the orientation of the hard magnetization axis from being disturbed while the easy magnetization axis of the fine particles 3 is being oriented, so that the orientation accuracy when the fine particles 3 are three-dimensionally oriented can be increased.

  FIG. 6 is a table showing the half-value widths of peaks obtained by X-ray diffraction of a sample quasi-single-crystallized by the fine particle orientation apparatus of the present invention. This half-value width indicates that the smaller the value, the higher the fine particle orientation accuracy. In the table of FIG. 6, lysozyme is quasi-single-crystallized under four types of test conditions A to D in which the rotation angle αq and angular velocity ωq during high-speed rotation and the rotation angle αs and angular velocity ωs during low-speed rotation are different. The X-ray diffraction result is shown.

6, condition A, the same conditions as the control method of the first embodiment (the angular velocity ωq is satisfies the relationship of the above formula (1), the predetermined time t _r, t _s, respectively the equation ( 2) to (4) are satisfied). The condition B may be the same conditions as the control method of the second embodiment (the angular velocity ωq is satisfies the relationship of the above formula (1), the predetermined time t _r, t _s, respectively the equation (2) To (4) is satisfied). Comparing Condition A and Condition B, it can be seen that Condition A has a smaller half-value width than Condition B. That is, when the rotation of the sample is substantially stopped during the three-dimensional alignment of the fine particles, it is understood that the alignment accuracy of the fine particles is higher when the sample is completely stopped than when the sample is rotated slowly.

  In the condition C, the rotation angles αq and αs are set to the same condition as the condition B, and the angular velocities ωq and ωs are set lower than the condition B, respectively. Comparing Condition B and Condition C, it can be seen that Condition B has a smaller half-value width than Condition C.

  On the other hand, in the condition D, the angular velocities ωq and ωs are set to the same condition as the condition B, the rotation angle αq is set smaller than the condition B, and the rotation angle αs is set larger than the condition B. Comparing condition B and condition D, it can be seen that condition B has a smaller half-value width than condition D. From the X-ray diffraction results of the conditions B to D, it is understood that when the rotation is performed at a low speed when the high-speed rotation is substantially stopped, if the rotation angle and the angular velocity of the condition B are set, the alignment accuracy of the fine particles is increased.

  7 is a drawing-substituting photograph showing an X-ray diffraction image of a sample quasi-single-crystallized under condition B in FIG. 6, and FIG. 8 is an X-ray diffraction image of a sample quasi-single-crystallized under condition D in FIG. FIG. (A), (b), and (c) in FIG. 7 correspond to (a), (b), and (c) in FIG. 8 respectively, and (a), (b), and (c) in both figures. ) Shows X-ray diffraction images of the ac plane, the bc plane, and the ab plane when the magnetization directions in the three directions of the fine particles are the a-axis, b-axis, and c-axis, respectively. When FIG. 7 is compared with FIG. 8, (a), (b), and (c) in FIG. 7 are more tails of the peak P than (a), (b), and (c) in FIG. It can be seen that the length is shortened and the orientation accuracy of the fine particles is high.

  FIG. 9 is a side view showing a schematic configuration of the fine particle orientation device according to the third embodiment of the present invention. The fine particle orientation device of the present embodiment is different from the first embodiment in that a time-varying magnetic field is applied by rotating the magnetic field generator 32 with the sample container 2 fixed.

  The fine particle orientation device includes a turntable 31, the magnetic field generation unit 32 mounted on the turntable 31, a drive unit 33 that rotates the magnetic field generation unit 32, and a control unit that drives and controls the drive unit 33. 34 and a base 35 on which the drive unit 33 is fixed.

  The magnetic field generator 32 includes a pair of left and right permanent magnets 32 a and 32 b fixed on the turntable 31. Each permanent magnet 32a, 32b is arranged so that the N pole and the S pole face each other. The sample container 2 is arranged above the permanent magnets 32a and 32b. The sample container 2 is fixed on the base 35 by a fixing member (not shown).

  The drive unit 33 is composed of, for example, a stepping motor, and the rotary table 31 is fixed to the rotary shaft 33a. The rotating shaft 33a is disposed directly below the fixed sample container 2. Thus, when the driving unit 33 is driven, the magnetic field generating unit 32 rotates around the fixed sample container 2 together with the rotating shaft 33a and the rotating table 31. At that time, the rotation speed of the magnetic field generator 32 is set to a speed necessary for forming the rotating magnetic field.

Control unit 34, the magnetic field generating unit 32 in a state of fixing the sample containers 2 are substantially 180 × n degrees (n is an arbitrary natural number) to each rotation of a predetermined period of time t _s required for forming a static magnetic field The drive unit 13 is drive-controlled so as to temporarily stop the rotation temporarily. Since the specific control method of the control unit 34 is the same as that of the first embodiment, the detailed description thereof is omitted.

  The base 35 is mounted on a goniometer (not shown), and when the goniometer is driven during X-ray structure analysis, the base 35 causes a precession motion that swings around the sample container 2. Thereby, the direction of the sample container 2 can be arbitrarily adjusted with respect to the X-ray a irradiated from the X-ray source (not shown) toward the sample container 2 from the right side of FIG.

  As described above, also in the fine particle aligning apparatus and the fine particle aligning method of the present embodiment, since the rotation of the magnetic field generating unit 32 is substantially stopped locally, the magnetic field generating unit 32 is slowed down over a wide range of 90 degrees as in the past. Compared with the case of rotating, the time for forming the static magnetic field can be shortened. Thereby, it is possible to prevent the orientation of the hard magnetization axis from being disturbed while the easy magnetization axis of the fine particles 3 is being oriented, so that the orientation accuracy when the fine particles 3 are three-dimensionally oriented can be increased.

  The present invention is not limited to the above-described embodiment, and can be implemented with appropriate modifications. For example, in the above embodiment, the relative rotation is substantially stopped every approximately 180 degrees, but the relative rotation is approximately stopped every plural rotations such as every 360 degrees (one rotation) or every 540 degrees (one and a half rotations). Alternatively, it may be stopped substantially at a different rotation angle each time. In short, it is only necessary to stop substantially when the relative rotation is performed up to an arbitrary natural number multiple of about 180 degrees.

  In the above embodiment, the predetermined time for relatively rotating the sample and the predetermined time for stopping the relative rotation of the sample are set so as to satisfy the relationship of the above expressions (2) and (3), respectively. Any one of the predetermined times may be set so as to satisfy the relationship of the above formula.

Further, in the third embodiment, when the relative rotation is substantially stopped, the relative rotation is stopped completely, but it may be rotated slowly locally.
Furthermore, in each of the above embodiments, a stepping motor is used as the drive unit, but other actuators such as a servo motor may be used.

DESCRIPTION OF SYMBOLS 1 Fine particle orientation apparatus 2 Sample container 3 Fine particle 12, 32 Magnetic field generation part 13, 33 Drive part 14, 34 Control part χ1, χ2, χ3 Magnetic susceptibility

Claims (10)

A fine particle orientation device for applying three-dimensional orientation of the fine particles by applying a time-varying magnetic field to a sample in which fine particles having different susceptibility in three directions orthogonal to each other are suspended.
A magnetic field generator,
A drive unit that rotates the sample relative to the magnetic field generation unit at a speed necessary to form a rotating magnetic field;
Each time the sample rotates approximately 180 × n degrees (n is an arbitrary natural number), the drive unit temporarily stops the relative rotation temporarily for a predetermined time required to form a static magnetic field. And a control unit that controls the driving of the fine particle aligning device.   2. The fine particle orientation device according to claim 1, wherein the control unit drives and controls the driving unit so as to temporarily stop the relative rotation every time the sample rotates 180 degrees.   The fine particle orientation device according to claim 1, wherein when the relative rotation is substantially stopped, the control unit drives and controls the drive unit so as to completely stop the relative rotation. The fine particle orientation device according to any one of claims 1 to 3, wherein a time for relatively rotating the sample is set so as to satisfy a relationship of the following formula.
_tr <δ ² / D ₁
Here, t _r is the time for relatively rotating the sample, [delta] is the permissible maximum half-width of the diffraction spot needed for X-ray structure analysis, D ₁ is the rotational diffusion coefficient around the axis of easy magnetization. The fine particle orientation device according to any one of claims 1 to 4, wherein the predetermined time for substantially stopping the relative rotation of the sample is set so as to satisfy the relationship of the following formula.
t _s <δ ² / D ₃
Here, t _s is a predetermined time to substantially stop the relative rotation of the sample, [delta] is the permissible maximum half-width of the diffraction spot needed for X-ray structure analysis, D ₃ is the rotational diffusion coefficient of around hard axis. 6. The fine particles according to claim 1, wherein the time for which the sample is relatively rotated and the predetermined time for which the relative rotation of the sample is substantially stopped are set to satisfy the relationship of the following formula. Orienting device.
_{t r / t s = 2 (} χ1-χ2) / (χ3-χ2)
Here, t _r is the time for relatively rotating the sample, t _s is a predetermined time to substantially stop the relative rotation of the sample, .chi.1 the magnetic susceptibility of the easy magnetization axis, chi-square magnetization of the intermediate shaft, Kai3 the magnetization hard axis Magnetic susceptibility (where χ1>χ2> χ3). The fine particle orientation device according to any one of claims 1 to 6, wherein a relative rotation speed of the sample is set so as to satisfy a relationship of the following formula.
ωq × 6ημ ₀ / (B ² (χ1-χ2)) >> 1/2
Where ωq is the angular velocity at which the sample rotates relatively, η is the viscosity coefficient of the suspension, μ ₀ is the permeability of vacuum, B is the magnetic field strength, χ 1 is the susceptibility of the easy axis, and χ 2 is the susceptibility of the intermediate axis. (Where χ1> χ2).   The fine particle orientation device according to any one of claims 1 to 7, wherein the driving unit rotates the sample.   The fine particle orientation device according to any one of claims 1 to 8, wherein the driving unit is a stepping motor. A fine particle orientation method in which a fine particle having different magnetic susceptibility in three directions orthogonal to each other is suspended in a sample by applying a time-varying magnetic field to three-dimensionally orient the fine particles.
The sample is rotated relative to the magnetic field generator at a speed necessary to form a rotating magnetic field,
Each time the sample rotates approximately 180 × n degrees (where n is an arbitrary natural number), the relative rotation is temporarily stopped temporarily for a predetermined time required to form a static magnetic field. Fine particle orientation method.