CN108535671B - Method for measuring nanoscale magnetization dynamics - Google Patents
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Abstract
The invention relates to the field of material surface magnetism measurement, in particular to a method for measuring nanoscale magnetization dynamics, wherein a measuring device comprises a pulse laser, a time delay device, an 1/4 wave plate, a concave lens, a convex lens I, a plane mirror, a polaroid, a beam splitter, a convex lens II, a lens platform, an atomic force microscope I, a probe I, a lens seat, an objective lens, a sample, a waveguide, a sample platform, a signal generator, an oscilloscope, a detector, a bias tee joint, an amplifier I, a mixer, an amplifier II, an analog-to-digital converter, a computer, an atomic force microscope II, a probe II and a phase sensitive detector, can measure a single nanostructure, can achieve submicron-order spatial resolution for measuring the magnetization dynamics of the surface of the sample, and adopts two different atomic force microscope tips to respectively carry out contact-mode atomic force microscope scanning and near-field time resolution magneto-optic effect experiments, and a frequency domain method is adopted to detect the magnetization dynamics of a GHz frequency band on the surface of the sample, so that the method has high sensitivity.
Description
Technical Field
The invention relates to the field of material surface magnetism measurement, in particular to a method for measuring nanoscale magnetization dynamics, which can measure high-frequency dynamic magnetization of a single nanostructure on the surface of a material.
Background
The magneto-optical Kerr effect measuring device is an important means in the research of the surface magnetism of materials, the working principle of the magneto-optical Kerr effect measuring device is based on the magneto-optical Kerr effect caused by the interaction between light and a magnetized medium, the magneto-optical Kerr effect measuring device not only can detect the magnetism of a material with a single atomic layer thickness, but also can realize non-contact measurement, and the magneto-optical Kerr effect measuring device has important application in the research of the aspects of the magnetic order, the magnetic anisotropy, the interlayer coupling, the phase change behavior of a magnetic ultrathin film and the like of the magnetic ultrathin. The magneto-optical Kerr effect measuring device mainly performs magnetization observation on the surface of a sample by detecting the light intensity change caused by the polarization state change of a beam of linearly polarized light after being reflected on the surface of a material, so that the imaging effect of the magneto-optical Kerr effect measuring device is extremely easy to be limited by an optical element, and the magneto-optical Kerr effect measuring device has the following defects in the prior art: the spatial resolution of the traditional focusing kerr microscope using a microscope objective is determined by the optical diffraction limit, so that the nanometer-scale magnetization dynamic characteristics cannot be obtained; the prior art has the following defects: the dynamic magnetization information with higher frequency in the sample can not be obtained, and the nanoscale magnetization dynamic measurement method can solve the problem.
Disclosure of Invention
In order to solve the problems, the invention provides a method for measuring the nanometer-scale magnetization dynamics, wherein a measuring device adopts a high-precision positioning device to obtain the magnetization information of the surface of a nanometer-scale sample, and adopts a frequency domain method to detect the magnetization dynamics of a GHz frequency band on the surface of the sample.
The technical scheme adopted by the invention is as follows:
the measuring device mainly comprises a pulse laser, a retarder, an 1/4 wave plate, a concave lens, a convex lens I, a plane mirror, a polaroid, a beam splitter, a convex lens II, a lens stage, an atomic force microscope I, a probe I, a lens holder, an objective lens, a sample, a waveguide, a sample stage, a signal generator, an oscilloscope, an optical bridge detector, a bias tee joint, an amplifier I, a mixer, an amplifier II, an analog-to-digital converter, a computer, an atomic force microscope II, a probe II, a phase sensitive detector, a sinusoidal signal generator, an incident light path and a reflection light path, wherein the input end of the optical bridge detector is provided with a polarizer with an angle of 45 degrees, the atomic force microscope II and the atomic force microscope I have the same structure, the probe I is positioned at the lower end of the atomic force microscope I, the probe II is positioned at the lower end of the atomic force microscope, the pulse laser, the signal generator, the waveguide and the oscilloscope are sequentially connected by cables, the optical bridge detector, the offset tee joint, the amplifier I, the mixer, the amplifier II, the analog-to-digital converter and the computer are sequentially connected by cables, a laser beam emitted by the pulse laser sequentially passes through the delayer, the 1/4 wave plate, the concave lens, the convex lens I, the plane mirror, the polaroid, the beam splitter, the convex lens II, the lens platform, the atomic force microscope I and the probe I to form an incident light path, reflected light generated by irradiating the laser beam on the surface of a sample sequentially passes through the probe I, the atomic force microscope I, the lens platform, the convex lens II and the beam splitter to form a reflected light path, the reflected light is deflected to the optical bridge detector by the beam splitter, the lens platform is a transparent disc and is provided with a central shaft, and the atomic force microscope I, the lens seat and the atomic force microscope II are respectively positioned below the lens, The probe I and the probe II are atomic force microscope probes with the same external dimension and are circular truncated cones in shape, the axes of the circular truncated cones are vertical to the horizontal plane, and the probe I is provided with a circular truncated cone-shaped through hole; the diameter of the upper bottom surface and the diameter of the lower bottom surface of the appearance circular truncated cone of the probe I and the probe II are respectively 3 micrometers and 2 micrometers, the diameter of an upper opening of the circular truncated cone-shaped through hole in the probe I is 500 nanometers, the diameter of a lower opening of the circular truncated cone-shaped through hole in the probe I is 900 nanometers, and the diameter of the lens table is ten centimeters; the waveguide has a length of 80 microns, a width of 50 microns, a thickness of 150 nanometers and a characteristic impedance of 50 ohms; the sample was 10 microns long, 9 microns wide and 50 nanometers thick.
The output end of the optical bridge detector is connected with the input end of a phase-sensitive detector, the reference frequency of the phase-sensitive detector is set to be consistent with the output frequency of the signal generator, the output end of the phase-sensitive detector is connected with the offset tee joint, and the output end of the sinusoidal signal generator is connected with the input end II of the frequency mixer. The input end of the optical bridge detector is provided with a polarizer with an angle of 45 degrees, and the reflected light passes through the polarizer and has light intensity of
Wherein I0Is the intensity of the reflected light, θ, as it reaches the polarizerkIs the kerr angle. The mixer has two signal inputs, input I and input II. When the dependence of the reflected light intensity on the sample magnetization is linear, it is possible to estimate the alternating component I ≈ I of the current in the optical bridge detector caused by the sample magnetizationDCθK0mzWherein thetaK0Is the Kerr angle, m, of the sample under magnetically saturated conditionszIs a change in out-of-plane magnetization, IDCIs the dc component of the current in the optical bridge detector.
The measuring device adopts a high-precision positioning device to obtain the magnetization information of the surface of the nanoscale sample, namely two different atomic force microscope needle points are adopted to respectively carry out contact mode atomic force microscope scanning and near-field time resolution magneto-optical Kerr effect experiments, and a frequency domain method is adopted to detect the magnetization dynamics of a GHz frequency band on the surface of the sample, so that the device has the advantages of high spatial sensitivity, high testing speed, simple structure and long service life of a probe.
The method for measuring the nanoscale magnetization dynamics comprises the following steps:
rotating the lens table to enable the atomic force microscope II to be located right above a sample, scanning a region containing the sample on the waveguide by using a probe II to obtain a surface topography image, preliminarily determining the position of the sample, retracting the probe II when the probe II is located at the edge of the sample, and recording each position parameter in the atomic force microscope II;
rotating the lens table to enable the atomic force microscope I to be positioned right above the sample, and inputting the position parameters recorded in the step one into the atomic force microscope I;
approaching the probe I to the surface of the sample, scanning the area of the sample by using the probe I at the scanning speed of 2nm/s, stopping approaching once the surface of the sample is detected, retracting upwards for 100nm, and closing the scanning feedback of the atomic force microscope I;
adjusting the position of the plane mirror to enable the laser beam to be emitted onto the probe I through the lens platform and the atomic force microscope I;
the pulse laser generates pulse laser with the period less than 100fs, the repetition rate of 50MHz and the wavelength of 700nm, and the trigger waveform of the signal generator is synchronous with the laser repetition rate;
generating RF current with the frequency f of 1GHz by a signal generator, and outputting the RF current to a waveguide for exciting a sample;
setting a probe I for scanning in a state of closing the scanning feedback of the atomic force microscope I;
the light beam reflected from the surface of the sample sequentially passes through a probe I, an atomic force microscope I, a lens stage, a convex lens II and a beam splitter and enters an optical bridge detector, and the polar Kerr signal with the frequency of 1GHz in the signal entering the optical bridge detector is separated by the phase sensitive detector and is output in a current form;
after the alternating current component of the current output by the phase sensitive detector is amplified by 30dB through an amplifier I, the alternating current component is input into an input end I of a mixer;
the sinusoidal signal generator locks the frequency to the signal generator, generating a reference signal with a frequency f- Δ f, Δ f being 3KHzThe reference signal is input to an input end II of the mixer;
the frequency of a mixing signal output by the mixer is delta f, the mixing signal is continuously amplified by an amplifier II, and finally the mixing signal is sampled by an analog-to-digital converter;
the computer records the signal output by the analog-to-digital converter and performs a fast fourier transform on the signal at the af frequency and correlates it with the sample position data acquired by the atomic force microscope I to obtain a magnetic resonance image of the sample surface.
The invention has the beneficial effects that:
the invention can measure a single nano structure, can achieve submicron-order spatial resolution on the measurement of the magnetization dynamic state of the surface of a sample, and has the advantages of higher spatial sensitivity, simple device and high test speed. The probe I and the probe II are atomic force microscope probes with the same outer edge size, and are respectively used for contact mode atomic force microscope scanning and near field time resolution magneto-optical Kerr effect experiments.
Drawings
The following is further illustrated in connection with the figures of the present invention:
FIG. 1 is a schematic of the present invention.
Fig. 2 is a bottom view of the lens stage.
In the figure, 1, a pulse laser, 2, a time delay, 3.1/4 wave plates, 4, a concave lens, 5, a convex lens I, 6, a plane mirror, 7, a polaroid, 8, a beam splitter, 9, a convex lens II, 10, a lens stage, 11, an atomic force microscope I, 12, a probe I, 13, a lens holder, 14, an objective lens, 15, a sample, 16, a waveguide, 17, a sample stage, 18, a signal generator, 19, an oscilloscope, 20, an optical bridge detector, 21, an offset tee joint, 22, an amplifier I, 23, a mixer, 24, an amplifier II, 25, an analog-to-digital converter, 26, a computer, 27, an atomic force microscope II, 28 and a probe II are arranged.
Detailed Description
As shown in fig. 1, the pulse laser 1, the signal generator 18, the waveguide 16, and the oscilloscope 19 are sequentially connected by cable, the optical bridge detector 20, the bias tee 21, the amplifier I22, the mixer 23, the amplifier II24, the analog-to-digital converter 25, and the computer 26 are sequentially connected by cable, the laser beam emitted by the pulse laser 1 sequentially passes through the retarder 2, the 1/4 wave plate 3, the concave lens 4, the convex lens I5, the flat mirror 6, the polarizer 7, the beam splitter 8, the convex lens II9, the lens stage 10, the atomic force microscope I11, and the probe I12 to form an incident optical path, the reflected light generated by the laser beam irradiating the surface of the sample 15 sequentially passes through the probe I12, the atomic force microscope I11, the lens stage 10, the convex lens II9, and the beam splitter 8 to form a reflected optical path, and the reflected light is deflected by the beam splitter 8 to the optical bridge detector 20, the probe II28 is a contact type atomic force microscope probe, the waveguide 16 is positioned on the sample table 17, the sample 15 is directly prepared on the upper surface of the waveguide 16 in a contact manner by a magnetron sputtering method, the probe I12 and the probe II28 are atomic force microscope probes with the same external dimension, the external shapes of the probes are circular truncated cones, the axes of the circular truncated cones are vertical to the horizontal plane, and a circular truncated cone-shaped through hole is formed in the probe I12; the diameter of the upper bottom surface of the appearance circular truncated cone of the probe I12 and the probe II28 is 3 micrometers, the diameter of the lower bottom surface of the appearance circular truncated cone of the probe I12 is 2 micrometers, the diameter of the upper opening of the circular truncated cone-shaped through hole in the probe I12 is 500 nanometers, the diameter of the lower opening of the circular truncated cone-shaped through hole in the probe I12 is 900 nanometers, and the diameter of the lens table 10 is ten centimeters; the waveguide 16 is 80 microns long, 50 microns wide, 150 nm thick, and has a characteristic impedance of 50 ohms; the sample 15 was 10 microns long, 9 microns wide and 50 nanometers thick.
As shown in fig. 2, the structure of the afm II27 is the same as that of the afm I11, the probe I12 is located at the lower end of the afm I11, the probe II28 is located at the lower end of the afm II27, the objective lens 14 is located at the lower end of the lens holder 13, the probe I12 and the probe II28 are probes of the same external dimensions, the lens holder 10 is a transparent disk and has a central axis, the afm I11, the lens holder 13 and the afm II27 are respectively located below the lens holder 10 and can be finely adjusted with respect to the position of the lens holder 10, and when the lens holder 10 rotates around the central axis, the afm I11, the lens holder 13 or the afm II27 can be respectively placed right above the sample 15.
The measuring device mainly comprises a pulse laser 1, a retarder 2, a 1/4 wave plate 3, a concave lens 4, a convex lens I5, a plane mirror 6, a polarizing plate 7, a beam splitter 8, a convex lens II9, a lens stage 10, an atomic force microscope I11, a probe I12, a lens holder 13, an objective lens 14, a sample 15, a waveguide 16, a sample stage 17, a signal generator 18, an oscilloscope 19, an optical bridge detector 20, a bias tee 21, an amplifier I22, a mixer 23, an amplifier II24, an analog-to-digital converter 25, a computer 26, an atomic force microscope II27, a probe II28, a phase sensitive detector, a sinusoidal signal generator, an incident light path and a reflection light path, wherein the input end of the optical bridge detector 20 is provided with a polarizer with an angle of 45 degrees, the atomic force microscope II27 has the same structure as the atomic force microscope I11, the probe I12 is positioned at the lower end of the atomic force microscope I11, the probe II28 is positioned at the lower end, the objective lens 14 is located at the lower end of the lens holder 13, the pulse laser 1, the signal generator 18, the waveguide 16 and the oscilloscope 19 are sequentially connected by a cable, the optical bridge detector 20, the offset tee joint 21, the amplifier I22, the mixer 23, the amplifier II24, the analog-to-digital converter 25 and the computer 26 are sequentially connected by a cable, a laser beam emitted by the pulse laser 1 sequentially passes through the retarder 2, the 1/4 wave plate 3, the concave lens 4, the convex lens I5, the plane mirror 6, the polarizer 7, the beam splitter 8, the convex lens II9, the lens stage 10, the atomic force microscope I11 and the probe I12 to form an incident light path, reflected light generated by the laser beam irradiating the surface of the sample 15 sequentially passes through the probe I12, the atomic force microscope I11, the lens stage 10, the convex lens II9 and the beam splitter 8 to form a reflected light path, and the reflected light is deflected to the optical bridge detector 20 by the beam splitter, the lens table 10 is a transparent disc and is provided with a central shaft, the atomic force microscope I11, the lens holder 13 and the atomic force microscope II27 are respectively positioned below the lens table 10 and can be finely adjusted relative to the position of the lens table 10, when the lens table 10 rotates around the central shaft, the atomic force microscope I11, the lens holder 13 or the atomic force microscope II27 can be respectively placed right above a sample 15, the probe II28 is a contact type atomic force microscope probe, the waveguide 16 is positioned on the sample table 17, the sample 15 is directly prepared on the upper surface of the waveguide 16 in a contact manner by a magnetron sputtering method, the probe I12 and the probe II28 are atomic force microscope probes with the same external dimension, the external shapes of the probes are round tables, the axes of the round tables are vertical to the horizontal plane, and the probe I12 is provided with a round table-shaped through hole; the diameter of the upper bottom surface of the appearance circular truncated cone of the probe I12 and the probe II28 is 3 micrometers, the diameter of the lower bottom surface of the appearance circular truncated cone of the probe I12 is 2 micrometers, the diameter of the upper opening of the circular truncated cone-shaped through hole in the probe I12 is 500 nanometers, the diameter of the lower opening of the circular truncated cone-shaped through hole in the probe I12 is 900 nanometers, and the diameter of the lens table 10 is ten centimeters; the waveguide 16 is 80 microns long, 50 microns wide, 150 nm thick, and has a characteristic impedance of 50 ohms; the sample 15 was 10 microns long, 9 microns wide and 50 nanometers thick.
The output end of the optical bridge detector 20 is connected with the input end of a phase sensitive detector, the reference frequency of the phase sensitive detector is set to be consistent with the output frequency of the signal generator 18, the output end of the phase sensitive detector is connected with a bias tee joint, and the output end of a sinusoidal signal generator is connected with the input end II of a mixer. The input end of the optical bridge detector 20 is provided with a polarizer with an angle of 45 degrees, and the reflected light passes through the polarizer and has light intensity of
Wherein I0Is the intensity of the reflected light, θ, as it reaches the polarizerkIs the kerr angle. The mixer 23 has two signal inputs, an input I and an input II. When the dependence of the reflected light intensity on the sample magnetization is linear, it is possible to estimate the alternating current component I ≈ I of the current in the optical bridge detector 20 due to the sample magnetizationDCθK0mzWherein thetaK0Is the Kerr angle, m, of the sample under magnetically saturated conditionszIs a change in out-of-plane magnetization, IDCIs the dc component of the current in the optical bridge detector.
The method for measuring the nanoscale magnetization dynamics comprises the following steps:
firstly, rotating the lens platform 10 to enable the atomic force microscope II27 to be positioned right above the sample 15, scanning a region containing the sample 15 on the waveguide 16 by using the probe II28 to obtain a surface topography image, primarily determining the position of the sample, retracting the probe II28 when the probe II28 is positioned at the edge of the sample 15, and recording each position parameter in the atomic force microscope II 27;
rotating the lens stage 10 to enable the atomic force microscope I11 to be located right above the sample 15, and inputting each position parameter recorded in the step one into the atomic force microscope I11;
approaching the probe I12 to the surface of the sample 15, then scanning the area of the sample 15 by using the probe I12 at the scanning speed of 2nm/s, stopping approaching once the surface of the sample is detected, retracting the distance upwards by 100nm, and simultaneously closing the scanning feedback of the atomic force microscope I11;
and fourthly, adjusting the position of the plane mirror 6 to enable the laser beam to pass through the lens platform 10 and the atomic force microscope I11 to be incident on the probe I12:
the pulse laser 1 generates pulse laser with the period less than 100fs, the repetition rate of 50MHz and the wavelength of 700nm, and the trigger waveform of the signal generator 18 is synchronous with the laser repetition rate;
the signal generator 18 generates RF current with the frequency f of 1GHz and outputs the RF current to the waveguide 16 for exciting the sample;
seventhly, under the state that the scanning feedback of the atomic force microscope I11 is closed, a probe I12 is arranged for scanning;
the light beam reflected from the surface of the sample 15 sequentially passes through a probe I12, an atomic force microscope I11, a lens table 10, a convex lens II9 and a beam splitter 8 and then enters the optical bridge detector 20, and the phase sensitive detector separates polar Kerr signals with the frequency of 1GHz from signals entering the optical bridge detector 20 and outputs the polar Kerr signals in a current form;
after the alternating current component of the current output by the phase sensitive detector is amplified by 30dB through an amplifier I22, the alternating current component is input to an input end I of the mixer 23;
the sine signal generator is frequency locked to the signal generator 18, generatingReference signal with frequency f- Δ f, Δ f being 3KHzThe reference signal is input to an input terminal II of the mixer 23;
eleven, the frequency of the mixed signal output by the mixer 23 is delta f, and the mixed signal is continuously amplified by an amplifier II24 and finally sampled by an analog-to-digital converter 25;
the computer 26 records the signal output by the analog-to-digital converter 25 and performs a fast fourier transform on the signal at the af frequency and correlates it with the sample position data acquired by the atomic force microscope I11 to obtain a magnetic resonance image of the sample surface.
The measuring device adopts a high-precision positioning device to obtain the magnetization information of the surface of the nanoscale sample, namely two different atomic force microscope needle points are adopted to respectively carry out contact mode atomic force microscope scanning and near-field time resolution magneto-optical Kerr effect experiments, and a frequency domain method is adopted to detect the magnetization dynamics of a GHz frequency band on the surface of the sample, so that the device has the advantages of high spatial sensitivity, high testing speed, simple structure and long service life of a probe. The invention can measure a single nano structure, can achieve submicron-order spatial resolution on the measurement of the magnetization dynamic state of the surface of a sample, and has the advantages of higher spatial sensitivity, simple device and high test speed.
Claims (1)
1. A measuring method of nanoscale magnetization dynamics is disclosed, wherein the measuring device mainly comprises a pulse laser, a retarder, an 1/4 wave plate, a concave lens, a convex lens I, a plane mirror, a polaroid, a beam splitter, a convex lens II, a lens platform, an atomic force microscope I, a probe I, a lens seat, an objective lens, a sample, a waveguide, a sample platform, a signal generator, an oscilloscope, an optical bridge detector, a bias tee joint, an amplifier I, a mixer, an amplifier II, an analog-to-digital converter, a computer, an atomic force microscope II, a probe II, a phase sensitive detector, a sinusoidal signal generator, an incident light path and a reflection light path, the input end of the optical bridge detector is provided with a polarizer with an angle of 45 degrees, the mixer is provided with an input end I and an input end II, the atomic force microscope II and the atomic force microscope I have the same structure, and the probe I is positioned at the, the probeThe probe II is positioned at the lower end of the atomic force microscope II, the objective lens is positioned at the lower end of the lens base, the pulse laser, the signal generator, the waveguide and the oscilloscope are sequentially connected by a cable, the optical bridge detector, the offset tee joint, the amplifier I, the mixer, the amplifier II, the analog-to-digital converter and the computer are sequentially connected by a cable, a laser beam emitted by the pulse laser sequentially passes through the delayer, the 1/4 wave plate, the concave lens, the convex lens I, the plane mirror, the polaroid, the beam splitter, the convex lens II, the lens platform, the atomic force microscope I and the probe I to form an incident light path, reflected light generated by the laser beam irradiating the surface of the sample sequentially passes through the probe I, the atomic force microscope I, the lens platform, the convex lens II and the beam splitter to form a reflected light path, the reflected light is deflected to the optical bridge detector by the beam splitter, and the lens, the atomic force microscope I, the lens seat and the atomic force microscope II are respectively positioned below the lens platform and can be finely adjusted relative to the position of the lens platform, when the lens platform rotates around the central shaft of the lens platform, the atomic force microscope I, the lens seat or the atomic force microscope II can be respectively arranged right above a sample, the probe II is a contact type atomic force microscope probe, the waveguide is positioned on the sample platform, the sample is directly prepared on the upper surface of the waveguide in a contact manner by a magnetron sputtering method, the probe I and the probe II are atomic force microscope probes with the same appearance size and are circular truncated cones in shape, the axes of the circular truncated cones are vertical to the horizontal plane, the probe I is provided with a circular truncated cone-shaped through hole, the diameters of the upper bottom surfaces and the lower bottom surfaces of the circular truncated cones in shape of the probe I and the probe II are 3 micrometers and 2 micrometers, and the diameter of the upper opening of the circular truncated cone-shaped through hole in the, The diameter of the lower opening is 900 nanometers, the diameter of the lens table is ten centimeters, the length of the waveguide is 80 micrometers, the width of the waveguide is 50 micrometers, the thickness of the waveguide is 150 nanometers, the characteristic impedance of the waveguide is 50 ohms, the length of the sample is 10 micrometers, the width of the sample is 9 micrometers, the thickness of the sample is 50 nanometers, the output end of the optical bridge detector is connected with the input end of the phase-sensitive detector, the reference frequency of the phase-sensitive detector is set to be consistent with the output frequency of the signal generator, the output end of the phase-sensitive detector is connected with the offset tee joint, the output end of the sinusoidal signal generator is connected with theThe light intensity of the incident light passing through the polarizer is
Wherein I0Is the intensity of the reflected light, θ, as it reaches the polarizerkIs the Kerr angle, when the dependence of the reflected light intensity on the sample magnetization is linear, it is possible to estimate the AC component I ≈ I of the current in the optical bridge detector caused by the sample magnetizationDCθK0mzWherein thetaK0Is the Kerr angle, m, of the sample under magnetically saturated conditionszIs a change in out-of-plane magnetization, IDCIs the dc component of the current in the optical bridge detector,
the method is characterized by comprising the following steps:
rotating the lens table to enable the atomic force microscope II to be located right above a sample, scanning a region containing the sample on the waveguide by using a probe II to obtain a surface topography image, preliminarily determining the position of the sample, retracting the probe II when the probe II is located at the edge of the sample, and recording each position parameter in the atomic force microscope II;
rotating the lens table to enable the atomic force microscope I to be positioned right above the sample, and inputting the position parameters recorded in the step one into the atomic force microscope I;
approaching the probe I to the surface of the sample, scanning the area of the sample by using the probe I at the scanning speed of 2nm/s, stopping approaching once the surface of the sample is detected, retracting upwards for 100nm, and closing the scanning feedback of the atomic force microscope I;
adjusting the position of the plane mirror to enable the laser beam to be emitted onto the probe I through the lens platform and the atomic force microscope I;
the pulse laser generates pulse laser with the period less than 100fs, the repetition rate of 50MHz and the wavelength of 700nm, and the trigger waveform of the signal generator is synchronous with the laser repetition rate;
generating RF current with the frequency f of 1GHz by a signal generator, and outputting the RF current to a waveguide for exciting a sample;
setting a probe I for scanning in a state of closing the scanning feedback of the atomic force microscope I;
the light beam reflected from the surface of the sample sequentially passes through a probe I, an atomic force microscope I, a lens stage, a convex lens II and a beam splitter and enters an optical bridge detector, and the polar Kerr signal with the frequency of 1GHz in the signal entering the optical bridge detector is separated by the phase sensitive detector and is output in a current form;
after the alternating current component of the current output by the phase sensitive detector is amplified by 30dB through an amplifier I, the alternating current component is input into an input end I of a mixer;
the sinusoidal signal generator locks the frequency to the signal generator, generating a reference signal with a frequency f- Δ f, Δ f being 3KHzThe reference signal is input to an input end II of the mixer;
the frequency of a mixing signal output by the mixer is delta f, the mixing signal is continuously amplified by an amplifier II, and finally the mixing signal is sampled by an analog-to-digital converter;
the computer records the signal output by the analog-to-digital converter and performs a fast fourier transform on the signal at the af frequency and correlates it with the sample position data acquired by the atomic force microscope I to obtain a magnetic resonance image of the sample surface.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103592468A (en) * | 2013-11-16 | 2014-02-19 | 中北大学 | Ferromagnetic resonance magnet exchange force microscope test system |
| CN204188496U (en) * | 2014-11-19 | 2015-03-04 | 漯河医学高等专科学校 | A kind of laser confocal microscope |
| CN104677865A (en) * | 2013-12-02 | 2015-06-03 | 大连光耀辉科技有限公司 | Microscopic analyzing device |
| CN104704375A (en) * | 2012-08-22 | 2015-06-10 | 哈佛学院院长及董事 | Nanoscale scanning sensors |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6437562B2 (en) * | 2000-03-27 | 2002-08-20 | Kabushiki Kaisha Toshiba | Magnetic field characteristics evaluation apparatus and magnetic field characteristics measuring method |
-
2018
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104704375A (en) * | 2012-08-22 | 2015-06-10 | 哈佛学院院长及董事 | Nanoscale scanning sensors |
| CN103592468A (en) * | 2013-11-16 | 2014-02-19 | 中北大学 | Ferromagnetic resonance magnet exchange force microscope test system |
| CN104677865A (en) * | 2013-12-02 | 2015-06-03 | 大连光耀辉科技有限公司 | Microscopic analyzing device |
| CN204188496U (en) * | 2014-11-19 | 2015-03-04 | 漯河医学高等专科学校 | A kind of laser confocal microscope |
Non-Patent Citations (3)
| Title |
|---|
| 原子力显微镜原理及磁畴测量;李崇香等;《河北北方学院学报（自然科学版）》;20150831;第31卷(第4期);第24-27、32页 * |
| 原子力显微镜的工作原理及其应用;徐井华等;《通化师范学院学报》;20130228;第34卷(第1期);第22-24页 * |
| 磁力显微镜及磁性涂层表面观测;孙克等;《磁记录材料》;19970331(第1期);第10-12页 * |
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