The magnetic microstructures of 2：17 type Sm （Co, Fe, Cu, Zr）z magnets were detected by magnetic force microscopy. Comparing the microstructures of the specimens eoated with and without Ta thin film before and afte...The magnetic microstructures of 2：17 type Sm （Co, Fe, Cu, Zr）z magnets were detected by magnetic force microscopy. Comparing the microstructures of the specimens eoated with and without Ta thin film before and after heat-treatment, it is found that： （a） as a protection layer, Ta coating layer about 20 nm thick can effectively restrain Sm volatilization under high temperature; （b） the stress built in the 2.17 type Sm-Co magnets during specimen preparation only affects some local parts of the domain structures; （c） the magnetic microstructures vary largely for specimens heat-treated at high temperature without Ta film coating due to Sm volatilization. In addition, by comparing with high coercivity Fe-Pt point tips, it is found that the Co-Cr thin-film tips are not suitable for detecting the magnetic microstructures of strong permanent magnets.展开更多
Many methods have been used to prepare the high-density perpendicular magnetic recording media. One of them is the electroless plating method. To study its potency for magnetic recording, the film’s magnetic structur...Many methods have been used to prepare the high-density perpendicular magnetic recording media. One of them is the electroless plating method. To study its potency for magnetic recording, the film’s magnetic structure is to be known. Magnetic force microscope (MFM) is a kind of scanning probe microscope (SPM). By controlling the scanning of a magnetized tip along the surface of the sample, MFM can image the magnetic field near the surface. MFM is widely used in studying magnetic head and magnetic structure of digits on disks, such as the size and shape of the digits, the recording noise of the media, the performance of rewriting and the capability to record展开更多
Mixed-valance manganites with strong electron correlation exhibit strong potential for spintronics,where emergent magnetic behaviors,such as propagation of high-frequency spin waves and giant topological Hall Effects ...Mixed-valance manganites with strong electron correlation exhibit strong potential for spintronics,where emergent magnetic behaviors,such as propagation of high-frequency spin waves and giant topological Hall Effects can be driven by their mesoscale spin textures.Here,we create magnetic vortex clusters with flux closure spin configurations in single-crystal La0.67Sr0.33MnO3 wire.A distinctive transformation from out-of-plane domains to a vortex state is directly visualized using magnetic force microscopy at 4 K in wires when the width is below 1.0μm.The phase-field modeling indicates that the inhomogeneous strain,accompanying with shape anisotropy,plays a key role for stabilizing the flux-closure spin structure.This work offers a new perspective for understanding and manipulating the non-trivial spin textures in strongly correlated systems.展开更多
文摘The magnetic microstructures of 2：17 type Sm （Co, Fe, Cu, Zr）z magnets were detected by magnetic force microscopy. Comparing the microstructures of the specimens eoated with and without Ta thin film before and after heat-treatment, it is found that： （a） as a protection layer, Ta coating layer about 20 nm thick can effectively restrain Sm volatilization under high temperature; （b） the stress built in the 2.17 type Sm-Co magnets during specimen preparation only affects some local parts of the domain structures; （c） the magnetic microstructures vary largely for specimens heat-treated at high temperature without Ta film coating due to Sm volatilization. In addition, by comparing with high coercivity Fe-Pt point tips, it is found that the Co-Cr thin-film tips are not suitable for detecting the magnetic microstructures of strong permanent magnets.
基金Work supported by the National Natural Science Foundation of China
文摘Many methods have been used to prepare the high-density perpendicular magnetic recording media. One of them is the electroless plating method. To study its potency for magnetic recording, the film’s magnetic structure is to be known. Magnetic force microscope (MFM) is a kind of scanning probe microscope (SPM). By controlling the scanning of a magnetized tip along the surface of the sample, MFM can image the magnetic field near the surface. MFM is widely used in studying magnetic head and magnetic structure of digits on disks, such as the size and shape of the digits, the recording noise of the media, the performance of rewriting and the capability to record
基金supported by the National Key Research and Development Program of China(2016YFA0302300)the Beijing Natural Science Foundation(Z190008)+9 种基金the National Natural Science Foundation of China(11974052 and 11474024)the Beamline 1W1A of the Beijing Synchrotron Radiation Facilitythe National Natural Science Foundation of China(11604011)Beijing Institute of Technology Research Fund Program for Young Scholarsthe National Natural Science Foundation of China(11672264 and 11621062)support by the German Research Foundation DFG SFB TRR173 Spin+X,project KL1811/18the Graduate School of Excellence Materials Science in Mainz(GSC266)Peking University was supported by the National Key R&D Program of China(2016YFA0300804)the National Natural Science Foundation of China(11974023 and 51672007)the Key R&D Program of Guangdong Province(2018B030327001 and 2018B010109009).
文摘Mixed-valance manganites with strong electron correlation exhibit strong potential for spintronics,where emergent magnetic behaviors,such as propagation of high-frequency spin waves and giant topological Hall Effects can be driven by their mesoscale spin textures.Here,we create magnetic vortex clusters with flux closure spin configurations in single-crystal La0.67Sr0.33MnO3 wire.A distinctive transformation from out-of-plane domains to a vortex state is directly visualized using magnetic force microscopy at 4 K in wires when the width is below 1.0μm.The phase-field modeling indicates that the inhomogeneous strain,accompanying with shape anisotropy,plays a key role for stabilizing the flux-closure spin structure.This work offers a new perspective for understanding and manipulating the non-trivial spin textures in strongly correlated systems.
