JP4977629B2 - Charged particle spin detector, microscope, and photoelectron spectrometer - Google Patents

Description

  The present invention relates to an analyzer that operates in a vacuum chamber and detects the magnetic moment of each charged particle.

  The Stern Gerlach method is known as a technique for decomposing neutron spin (Non-patent Document 1). The principle is shown in FIG. First, as shown in FIG. 1A, consider a space in which a magnetic field having a large vertical component is applied to the orbit of the neutron 104 and the magnetic field strength has a gradient in the vertical direction. The magnetic field is applied by a pair of magnetic poles arranged at a position perpendicular to the traveling direction of the neutron 104. One of the magnetic poles has a concave surface with respect to the orbit of the neutron, and the other magnetic pole has a convex surface with respect to the concave surface. When the magnetic field generated from the convex magnetic pole reaches the concave surface, a magnetic field having the above gradient is formed. Here, the density of the magnetic lines of force is higher in the upper direction as viewed from the charged particle orbit. As shown in FIG. 1B, when a neutron having a magnetic moment parallel and antiparallel to the direction of the magnetic field gradient is incident, an upward and downward force is received, and the orbit changes due to the force. Thus, the magnetic moment can be decomposed. Even if the force received from the magnetic field gradient is very small, neutrons do not receive any other force, so that the magnetic moment can be resolved by changing the orbit. If the magnetic moment of the neutron has a transverse component, the component precesses around the direction of the magnetic field, so it is not kept constant and is not subjected to the force due to the magnetic field gradient. Several patents relating to magnetic moment detection using this method are also disclosed (for example, Patent Documents 1 and 2).

  The separation of neutron orbits due to the above effects is very small. In fact, we have developed a method that utilizes the difference in convergence due to the direction of the magnetic moment by using the Rabi method that combines the two (non-convergence) Patent Document 2).

JP 2001-099815 A Japanese Unexamined Patent Publication No. 07-174831 New Physics Series 27, supervised by Yasuhiko Yamauchi, “Spin and Polarization”, p57 (October 1994, published by Baifukan) New Physics Series 27, supervised by Yasuhiko Yamauchi, “Spin and Polarization”, p62 (October 1994, published by Baifukan)

  However, this Stern-Gerlach method cannot be applied to charged particles such as electrons and ions. That is, when a charged particle passes through a magnetic field, even if it is a small energy of several eV, it receives a Lorentz force that is overwhelmingly larger than the force that the magnetic moment receives from the magnetic field gradient. This is because the difference in the trajectory due to the force exerted on the can no longer be resolved. For example, in FIG. 1, if the neutron is a charged particle, the charged particle receives a force in the vertical direction due to the interaction between the magnetic moment and the magnetic field gradient, but receives a much larger Lorentz force in the horizontal direction. Moreover, since the Lorentz force varies depending on the position of the charged particles due to the magnetic field gradient, the charged particle trajectory is dispersed. As a result, the magnetic moment cannot be resolved by the orbit. Therefore, for example, Mott scattering (for example, Japanese Journal of Applied Physics 45, page 6468 (2006) (Jpn.J.Appl.Phys. 45, 6468 (2006)) ) Etc., the efficiency is three or more orders of magnitude lower than that of ordinary electron detectors.

  An object of the present invention is to provide a charged particle spin detector capable of decomposing a magnetic moment of charged particles with high efficiency, and various application devices using the same.

  In the present invention, in order to achieve the above object, a pair of magnetic poles for applying a magnetic field having a gradient to incident charged particles and an electric field for canceling the Lorentz force that the charged particles receive from the magnetic field are charged particles. A charged particle spin detector that decomposes the magnetic moment of the charged particle in the magnetic field direction by the interaction of the magnetic field gradient and the magnetic moment of the charged particle, and an application device using the same To do.

  In addition, in the present invention, the shape of the magnetic pole and electrode is extremely important, and the magnetic field gradient can be easily created on the charged particle orbit by using the magnetic poles having different shapes such as a convex and concave shape on the N side and the S side. Can do. Furthermore, it is preferable not to create a uniform electric field with respect to the electrodes but to cancel the Lorentz force that the charged particles receive in the orbit. For example, two flat electrodes are not parallel to each other but have an inclination angle. Hold and place. Furthermore, the pair of electrodes is formed by a hyperbolic column or a rectangular column approximating it.

  ADVANTAGE OF THE INVENTION According to this invention, the magnetic moment which each charged particle has can be decomposed | disassembled, and a charged particle spin detector which is remarkably efficient can be provided.

  The present invention provides a detector that decomposes the magnetic moment of charged particles with high efficiency. Before describing various embodiments of the present invention, its basic structure will be described with reference to FIGS. 2A and 2B and FIG.

  2A and 2B show the basic structure of a charged particle spin detector used in the present invention. As shown in FIG. 2A, as in the Stern-Gerlach method, the N-pole magnetic pole 201 and the S-pole magnetic pole 202 have different shapes. In the configuration shown in FIG. 2A, the S-pole is on the orbit side of the incident charged particle. The concave surface and the N magnetic pole are formed as convex surfaces. Although the two electrodes 203 have the same flat plate shape, an electric field having a curvature is created by arranging them so as to be inclined with respect to the longitudinal central axis of the N magnetic pole. Both the magnetic lines of force 204 and the electric lines of force 205 generated in such a state have different directions and densities depending on locations. In this state, as shown in FIG. 2B, charged particles 206 are incident in the vertical direction of the drawing. The charged particles receive a Lorentz force from the magnetic field lines 204, but receive an electrostatic force from the electric field lines 205 to cancel the Lorentz force. That is, such magnetic field lines 204 and electric field lines 205 must be generated. In this case, the force received by the charged particle 206 is only the force 207 received from the magnetic field gradient, and the direction of the force differs depending on the magnetic moment 206 of the charged particle. it can.

  FIG. 3 shows a cross-sectional structure of the charged particle spin detector shown in FIGS. 2A and 2B, cut in the vertical direction of the paper of FIG. 2B. In this figure, charged particles 304 enter the magnetic poles 301 and 302 and the electrode 303 from the right side of the paper, and receive a force corresponding to the direction of the magnetic moment from the magnetic field gradient and pass through the magnetic poles 301 and 302 and the electrode 303. The orbit changes. The charged particles whose orbits are separated are captured by the charged particle detector 305, and their magnetic moments can be resolved.

The efficiency of the conventional Mott detector is about 1 × 10 ⁻⁴ , and the improvement of the efficiency is a big issue. The spin detector according to the present invention can theoretically have an efficiency of 1 if the orbital separation due to the magnetic field gradient can be made sufficiently large. In other words, the efficiency of the conventional Mott detector can be improved by about 4 digits.

  The amount of deflection due to the force received by the electron spin from the magnetic field gradient described above is assumed to be 1.4 μm when the acceleration 10V electron travels 1 m in the magnetic field gradient of 1 T / m. This deflection amount is proportional to the square of the traveling distance of electrons.

  As described above, when magnetic poles having different shapes on the N side and the S side are used, a magnetic field gradient can be easily created on the charged particle orbit. Also, the electrode does not create a uniform electric field, but cancels the Lorentz force that the charged particles receive in the orbit. For example, two flat electrodes are not parallel to each other but have an inclination angle. It is conceivable to arrange them. It is also conceivable to use a hyperbolic column for the electrode or a rectangular column approximating it. By making the electrode surface shape (at least the side facing the orbital side of the charged particle beam) into a hyperbolic column or a prism, the equipotential surface or the isomagnetic potential surface becomes a hyperbola and obtains an excellent convergence effect. Can do.

  The first embodiment will be described below with reference to FIG.

  FIG. 4 shows a specific example 1 to which the basic configuration described in FIGS. 2A, 2B, and 3 is applied. A plurality of combinations of the aforementioned magnetic poles and electrodes are prepared and arranged in the charged particle trajectory direction. If the force received by the magnetic moment of a charged particle from the magnetic field gradient of a pair of magnetic poles and electrodes is not sufficient, a sufficient orbit can be obtained by preparing multiple combinations of these and integrating the force received from the magnetic field gradient. Change.

  In this embodiment, the charged particles first enter the magnetic poles 401 and 402 and the electrode 403. Here again, the Lorentz force and the electrostatic force are canceled as in the basic configuration described above. Thereafter, the charged particles enter the magnetic poles 404 and 405 and the electrode 406. Here, the magnetic poles 401 and 402, 404 and 405 generate a magnetic field in the opposite direction, and the shape of the magnetic pole is reversed, so the density distribution of the magnetic field lines is also reversed. As a result, the direction of the magnetic field gradient is the same. Therefore, the force that the magnetic moment of the charged particle receives from the magnetic field gradient created by the magnetic poles 401 and 402, 404 and 405 is in the same direction. However, since the directions of the magnetic fields generated by the respective magnetic poles are different, the Lorentz forces are in opposite directions and can be canceled with each other. That is, even if the Lorentz force cannot be completely canceled by electrostatic force, the Lorentz force can be canceled if the combination of a plurality of electrodes and magnetic poles is arranged well in this way.

  In this embodiment, the charged particles then enter the magnetic poles 407 and 408, the electrode 409, the magnetic poles 410 and 411, and the electrode 412. Here again, the direction of the magnetic field generated by the magnetic poles 407 and 408 and the gradient of the magnetic field line density are opposite to those generated by the magnetic poles 410 and 411. In this way, by arranging an appropriate number of combinations of magnetic poles and electrodes, the force received from the magnetic field gradient can be increased, and the force received from others such as Lorentz force can be reduced, thereby improving the resolution of the magnetic moment. be able to. From the viewpoint of canceling the Lorentz force, the number of combinations of magnetic poles and electrodes is desirably an even number. Of course, in all combinations, the optical axis 410 of the charged particles needs to match.

  FIG. 5 is a diagram showing the configuration of the second embodiment. The method described above can only resolve spins in one direction perpendicular to the traveling direction of the electron beam. In order to resolve spins in other directions by the charged particle spin detector, it is necessary to rotate the spins in the undetectable direction in the detectable direction before entering. In the present embodiment, one or two spin rotators 506 and 507 capable of fulfilling such a role are arranged in front of the charged particle spin detector so that spins in other directions can be detected. . The spin rotator has the same structure as an energy analyzer called Wien filter in which the electric and magnetic fields are orthogonal to each other and the charged particle orbit (for example, Review of Scientific Instruments 75, 2003 (2004 (Rev. Sci. Instrum. 75, 2003 (2004)) and solenoid coils.

  By using two types of Wien filter type or a combination of Wien filter type and solenoid type, any direction of electron spin can be directed to a direction that can be detected by the charged particle spin detector according to this embodiment. it can. For example, when the spin rotator is not operated at all, it is possible to detect the spin component in the vertical direction in FIG. In the embodiment shown in FIG. 5, the spin component parallel to the charged particle trajectory is detected. In addition, if the charged particle spin is rotated 90 degrees in the vertical direction in FIG. 5, the spin component in the direction perpendicular to the paper surface can be detected. By detecting the spins in the above three directions, the spin direction of the charged particles can be determined three-dimensionally.

  FIG. 6 is a diagram showing a third embodiment, which has a configuration in which the configuration of the second embodiment shown in FIG. 4 is combined with the rabbi technique described above. Here, let us consider a process in which a charged particle beam is transmitted through a gradient magnetic field while having a convergence effect. The charged particle 601 moves from the right to the left in the drawing, has a magnetic moment 602, and passes between the magnetic poles 603 and 604 creating a magnetic field gradient, as in the previous embodiment. An electrode for canceling the Lorentz force is omitted in the figure. For example, it is assumed that the charged particle 601 receives a force upward in the figure due to the interaction between the magnetic moment 602 and the magnetic field gradient. Thereafter, the charged particle 601 passes through a region 605 where a magnetic field is applied in the vertical direction of the drawing. Due to the magnetic field applied at this time, the magnetic moment rotates to make a Larmor precession. Then, by adjusting the strength of the magnetic field, it is transmitted between the magnetic poles 606 and 607 that create a magnetic field gradient again when the magnetic moment is reversed. The magnetic field gradient in the magnetic poles 606 and 607 is compared with that in the magnetic poles 603 and 604, so that the magnetic moment 602 that has been reversed is reversed from the magnetic field gradient by reversing the polarity of the magnetic field or reversing the direction of the gradient. Similarly, receive upward force.

  By passing through the two-step magnetic field gradient in this way, the trajectory of the charged particle 601 is slightly shifted upward. If the charged particle has no magnetic moment, the charged particle beam is focused on the convergence point 609, but reaches a position 608 away from the convergence point 609 depending on the magnitude of the magnetic moment. As described above, by examining the convergence characteristics of the charged particle beam at the convergence point, information on the magnitude and direction of the magnetic moment can be extracted. In this embodiment, two pairs of magnetic poles are used. Of course, two or more pairs may be used. If the number is increased, there is an advantage that the deviation of the charged particle convergence point due to the magnetic moment can be increased.

  FIG. 7 is a diagram showing the configuration of the fourth embodiment. The magnetic pole for creating the magnetic field gradient and the electrode for canceling the Lorentz force received by the charged particles are arranged as one unit 701 on a plurality of unit circumferences. However, it is necessary to leave a portion where charged particles 702 are incident. This unit may be provided with a magnetic pole for generating a magnetic field for reversing the magnetic moment in the embodiment shown in FIG. In such a state, charged particles 702 are made incident on the circumference, and the electromagnetic field in the unit is controlled so that the charged particles rotate on the circumference. In the present embodiment, it is assumed that the magnetic field in the unit is oriented in the vertical direction of the drawing, and that the magnetic moment in the vertical direction of the drawing is decomposed. Although the force received by the magnetic moment of the charged particles in each unit is weak, the magnetic moment is received from the magnetic field gradient because it makes a circular motion many times and passes through multiple units arranged on the circumference many times. If you integrate the force well, it will show up as a big trajectory difference. Then, when the change of the trajectory becomes sufficiently large, it enters the charged particle detector 703 at a position slightly away from the charged particle trajectory in the vertical direction in the drawing and is counted. By utilizing such circular motion of charged particles, it is possible to integrate a weak force and resolve a magnetic moment.

  Although FIG. 7 shows an example with seven units 701, it goes without saying that this number is not limited to seven.

  FIG. 8 shows an embodiment of a spin-polarized scanning electron microscope equipped with the charged particle spin detector described above. A spin-polarized scanning electron microscope is a device that obtains a magnetic domain image by mapping the degree of spin polarization of secondary electrons emitted from a magnetic sample. For example, Japanese Patent Application Laid-Open No. 60-177539 It has been published. The primary electron beam 802 emitted from the electron gun 801 is irradiated to the sample 804 set on the sample stage 803. Up to this point, it is the same as a normal SEM, but in a spin-polarized scanning electron microscope, a secondary electron collecting optical system 805 is arranged near the sample, carrying as many secondary electrons 806 as possible, and resolving those spins. There is a need. Therefore, a secondary electron transport optical system 807 that transports the secondary electrons 806 must be arranged and transported to the spin detection system while adjusting the lens characteristics of these optical systems. An example of voltages to be applied to the respective electron lenses of the secondary electron collecting optical system 805 and the secondary electron transport optical system 807 is shown in the drawing.

  The secondary electrons 806 then reach the spin rotator 808, rotate the component of the electron spin to be detected in a direction that can be detected by the charged particle spin detector 809, and then be transported to the charged particle spin detector 809. If two spin rotators 808 are mounted as in the second embodiment, the spins in any direction can be directed in the detectable direction. The charged particle spin detector 809 preferably has a structure as shown in the fourth embodiment shown in FIG. 7, for example, as shown in an enlarged view.

  A signal from the charged particle spin detector 809 enters a signal processing system 810 that is a signal processing unit, and a magnetic domain image is created by an image processing system 811 that is an image processing unit. The image processing system 812 also controls the spin rotator 808 so that it can select which direction spins are imaged. This image processing system 811 is also connected to an electron beam controller 812 that controls the electron gun 801, and creates a magnetic domain image by fusing the position of the primary electron beam 802 on the sample with the signal from the signal processing system 810. ing. It covers the primary electron beam 802, the sample stage 803, the sample 804, the secondary electron 806, the secondary electron collection optical system 805, the secondary electron transport optical system 807, the spin rotator 808, and the charged particle spin detector 809. The vacuum chamber is omitted in this figure. Although the above-mentioned spin-polarized scanning electron microscope is a technique that has already been reported, by installing the above-mentioned charged particle spin detector 809, it is possible to obtain data with significantly better S / N than before, In addition, a spin-polarized scanning electron microscope capable of acquiring a large amount of data in a short time can be provided.

  FIG. 9 shows an embodiment of an atom probe or a field ion microscope equipped with a charged particle spin detector. An atom probe estimates the atomic position and the type of atoms by applying an electric field to a sharpened sample and measuring the emission direction of the atoms emitted from the sample tip and the time of flight to the detector. is there. The field ion microscope is basically the same as the atom probe except that it does not measure the time of flight. Such an atom probe sample 901 is prepared, and an electric field is applied to emit atoms 902 from the tip. Among the emitted atoms, an atom that has jumped out in a specific direction is selected using the aperture 903, and the atom is taken into the charged particle spin detector 904 described above. As a result, information on the magnetic moment of the atoms can be obtained by measurement with an atom probe or a field ion microscope, and magnetization information of each atom that has not been obtained conventionally can be obtained.

  FIG. 10 shows an example of a scanning ion microscope equipped with a charged particle spin detector. When the accelerated ion beam 1001 enters the sample 1002, atoms on the sample surface are ejected and jump out into the vacuum. If this atom 1003 is incorporated into the charged particle spin detector 1004 of the present invention, knowledge about the magnetization vector of the sample can be obtained. If the incident ion beam is scanned by this method, a magnetic domain image on the sample surface can be obtained. At this time, internal electrons are also emitted from the sample surface by the ion beam 1001, and if the electrons are guided to the charged particle spin detector 1004, the same information as the spin-polarized scanning electron microscope can be obtained. Needless to say, in this embodiment, when the ion beam is replaced with a primary electron beam, an embodiment of a spin-polarized scanning electron microscope is obtained.

  FIG. 11 shows an embodiment of a photoelectron spectrometer equipped with a charged particle spin detector. When an electromagnetic wave 1101 having a predetermined energy enters the sample 1102, electrons at a level corresponding to the energy of the incident electromagnetic wave jump out into the vacuum as photoelectrons 1103. If this photoelectron 1103 is taken into the charged particle spin detector 1104 of the present invention, knowledge about the magnetic moment of each element constituting the sample 1102 can be obtained. This method is known as spin-resolved photoelectron spectroscopy (for example, Japanese Journal of Applied Physics No. 35, p. 6314 (1996) (Jpn.J.Appl.Phys. 35, 6314 (1996) ), A Mott detector has been used in the past, and its sensitivity is not sufficient.By mounting the charged particle spin detector 1104 described above, it is possible to obtain data with much better S / N than before, A large amount of data can be acquired in a short time.

  FIG. 12 shows an embodiment relating to a preferred structure of the charged particle detector. The N pole magnetic pole 1201 and the S pole magnetic pole 1202 are the same as the structure of the embodiment shown in FIG. 2, but the electrode 1203 for creating an electric field that cancels the Lorentz force is formed into a hyperbolic column shape, and as a result, Both electric field lines 1205 have a curvature. This is because the hyperbolic equipotential surface and the isomagnetic potential surface are advantageous for the charged particle beam convergence in a field where the electric field and the magnetic field are orthogonal to each other. This is because Scientific Instruments 66, page 5537 (1995) (Rev. Sci. Instrum. 66, 5537 (1995)), is expected to have the same effect with this charged particle spin detector.

  FIG. 13 shows an embodiment relating to another structure of the charged particle detector. The N-pole magnetic pole 1301 and the S-pole magnetic pole 1302 have the same structure as that of the embodiment shown in FIG. 2, but the electrode 1303 for generating an electric field that cancels the Lorentz force is a prism that approximates a hyperbolic cylinder. Although it is not easy to accurately form a hyperbolic column shape as shown in FIG. 12, if it is approximated by such a prismatic shape, manufacture is easy. As a result, both the magnetic lines of force 1304 and the electric lines of force 1305 obtained have a curvature, and the same effect can be obtained.

It is a figure which shows the positional relationship of the magnetic field with the gradient which they produce, the gradient which they produce, and a neutron beam for demonstrating the principle of the Stern-Gerlach method which decomposes | disassembles the magnetic moment of a neutron. It is a figure which shows the force which the magnetic moment of a neutron beam receives from the magnetic field gradient for demonstrating the principle of the Stern-Gerlach method which decomposes | disassembles the magnetic moment of a neutron. It is a figure which shows the relationship between the magnetic pole and electrode of the charged particle spin detector of this invention, and the magnetic field and electric field which they produce. It is a figure which shows the magnetic moment of charged particles and the force which they receive from a magnetic field gradient in the charged particle spin detector of this invention. It is a figure which shows a mode that the track | orbit of a charged particle is decomposed | disassembled in the charged particle spin detector of this invention. It is a figure which shows the structure of the charged particle spin detector which concerns on a 1st Example. It is a figure which shows the structure of the charged particle spin detector which concerns on a 2nd Example. It is a figure which shows the structure of the charged particle spin detector which concerns on a 3rd Example. It is a figure which shows the structure of the charged particle spin detector which concerns on a 4th Example. It is a figure which shows the structure of the spin polarization scanning electron microscope which mounts the charged particle spin detector based on a 5th Example. It is a figure which shows the principal part structure of the atom probe or field ion microscope which mounts the charged particle spin detector based on a 6th Example. It is a figure which shows the principal part structure of the scanning ion microscope which mounts the charged particle spin detector based on a 7th Example. It is a figure which shows the principal part structure of the spin decomposition photoelectron spectrometer which mounts the charged particle spin detector based on an 8th Example. It is a figure which shows the structure of the charged particle spin detector which concerns on a 9th Example. It is a figure which shows the structure of the charged particle spin detector which concerns on a 10th Example.

Explanation of symbols

101: Magnetic pole (N pole), 102: Magnetic pole (S pole), 103: Magnetic field lines, 104: Neutron beam incident direction, 105: Direction of neutron and its magnetic moment, 106: Direction of force that neutron receives from magnetic field gradient,
201 ... Magnetic pole (N pole), 202 ... Magnetic pole (S pole), 203 ... Electrode, 204 ... Line of magnetic force, 205 ... Line of electric force, 206 ... Direction of charged particle and magnetic moment, 207 ... Charged particle receives from magnetic field gradient Direction of power,
301 ... Magnetic pole (N pole), 302 ... Magnetic pole (S pole), 303 ... Electrode, 304 ... Charged particle, 305 ... Charged particle detector,
401 ... magnetic pole (N pole), 402 ... magnetic pole (S pole), 403 ... electrode, 404 ... magnetic pole (S pole), 405 ... magnetic pole (N pole), 406 ... electrode, 407 ... magnetic pole (N pole), 408 ... Magnetic pole (S pole), 409 ... Electrode, 410 ... Magnetic pole (N pole), 411 ... Magnetic pole (S pole), 412 ... Electrode, 413 ... Optical axis of charged particle,
501 ... Magnetic pole (N pole), 502 ... Magnetic pole (S pole), 503 ... Electrode, 504 ... Charged particle, 505 ... Charged particle detector, 506 ... Spin rotator, 507 ... Spin rotator,
601 ... Charged particle, 602 ... Magnetic moment of charged particle, 603 ... Magnetic pole (S pole), 604 ... Magnetic pole (N pole), 605 ... Magnetic field application area, 606 ... Magnetic pole (N pole), 607 ... Magnetic pole (S pole) 608 ... charged particle beam arrival point with magnetic moment, 609 ... charged particle beam convergence point without magnetic moment,
701 ... Magnetic pole creating magnetic field gradient and electrode unit canceling Lorentz force, 702 ... Charged particle, 703 ... Electron detector,
801 ... Electron gun, 802 ... Primary electron beam, 803 ... Sample stage, 804 ... Sample, 805 ... Secondary electron collection optical system, 806 ... Secondary electron, 807 ... Secondary electron transport optical system, 808 ... Spin rotator 809 ... charged particle spin detector, 810 ... signal processing system, 811 ... image processing system, 812 ... electron beam controller
901 ... Atom probe sample, 902 ... Atom emitted from sample, 903 ... Aperture, 904 ... Charged particle spin detector,
1001 ... incident ion beam, 1002 ... sample, 1003 ... atoms emitted from the sample, 1004 ... charged particle spin detector,
1101 ... electromagnetic wave, 1102 ... sample, 1103 ... photoelectrons emitted from the sample, 1104 ... charged particle spin detector,
1201 ... Magnetic pole (N pole), 1202 ... Magnetic pole (S pole), 1203 ... Electrode, 1204 ... Magnetic field lines, 1205 ... Electric field lines,
1301 ... Magnetic pole (N pole), 1302 ... Magnetic pole (S pole), 1303 ... Electrode, 1304 ... Magnetic field lines, 1305 ... Electric field lines.

Claims (17)

A charged particle spin detector comprising:
A pair of magnetic poles for applying a magnetic field having a gradient to the incident charged particles;
A pair of electrodes for applying to the charged particles an electric field that cancels the Lorentz force that the charged particles receive from the magnetic field;
The magnetic moment in the magnetic field direction of the charged particles is decomposed by the interaction between the gradient of the magnetic field and the magnetic moment of the charged particles.
A charged particle spin detector. The charged particle spin detector according to claim 1,
One of the pair of magnetic poles is provided with a concave surface on the orbit side of the charged particle, and the charged particle spin detector. The charged particle spin detector according to claim 1,
One of the pair of magnetic poles is provided with a convex surface on the orbit side of the charged particle, and the charged particle spin detector. The charged particle spin detector according to claim 1,
The pair of electrodes are two plate electrodes arranged to be inclined with respect to each other.
A charged particle spin detector. The charged particle spin detector according to claim 1,
The cross-sectional shape of the pair of electrodes is a hyperbolic column or a prism.
A charged particle spin detector. The charged particle spin detector according to claim 1,
A plurality of the pair of magnetic poles and the pair of electrodes are arranged in the traveling direction of the charged particles,
The polarity of the plurality of the pair of magnetic poles arranged and the polarity of the potential applied to the pair of electrodes are different from each other with respect to the traveling direction of the charged particles,
A charged particle spin detector. The charged particle spin detector according to claim 6,
A plurality of the pair of electrodes and the pair of magnetic poles are arranged on a circumference;
By rotating the charged particle trajectory a predetermined number of times on the circumference, the magnetic moment decomposition effect due to the magnetic field gradient is enhanced.
A charged particle spin detector. The charged particle spin detector according to claim 1,
Before the charged particle enters the charged particle spin detector, it has a mechanism for rotating the direction of the charged particle spin, and can detect the charged particle spin in any direction using the mechanism.
A charged particle spin detector. The charged particle spin detector according to claim 8,
The mechanism for rotating the direction of the charged particle spin includes a Wien filter type having a mechanism for orthogonally crossing an electric field and a magnetic field,
A charged particle spin detector. The charged particle spin detector according to claim 8,
The mechanism for rotating the direction of the electron spin is composed of two spin rotators, and at least one of the spin rotators is a Wien filter type.
A charged particle spin detector. The charged particle spin detector according to claim 1.
A spin-resolved photoelectron spectrometer characterized by that. The charged particle spin detector according to claim 1.
An atom probe microscope characterized by that. The charged particle spin detector according to claim 1.
A field ion microscope characterized by that. The charged particle spin detector according to claim 1.
A scanning ion microscope characterized by that. The charged particle spin detector according to claim 1.
A spin-polarized scanning electron microscope. A spin-polarized scanning electron microscope that detects electron spin polarization and observes a sample,
An electron gun that emits a primary electron beam;
A sample stage carrying a sample irradiated with the primary electron beam;
A secondary electron collecting optical system that converges secondary electrons emitted from the sample by irradiation of the primary electron beam;
A secondary electron transport optical system for transporting the collected secondary electrons;
A spin detector for detecting spin polarization of the transported secondary electrons;
A signal processing unit for processing the output signal of the spin detector;
The spin detector is
A pair of magnetic poles for applying a magnetic field having a gradient to the secondary electrons;
A pair of electrodes for applying to the secondary electrons an electric field that cancels out the Lorentz force received by the secondary electrons from the magnetic field;
A spin-polarized scanning electron microscope. The spin-polarized scanning electron microscope according to claim 16,
A mechanism was installed between the secondary electron transport optical system and the spin detector to rotate the direction of electron spin of the secondary electrons.
A spin-polarized scanning electron microscope.

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