| Effect of Post Annealing on the Microstructure and Magnetic Properties of NdFeB/α-Fe/NdFeB Thin Films |
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| 作者单位： | Zhang Lina（College of Materials Science and Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, China） ;
Zhang Mingang（College of Materials Science and Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, China） ;
Yi Meiqing（College of Materials Science and Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, China） ; |
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| 基金项目： | Project supported by Natural Science Foundation of Shanxi Province (20021067) |
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| 摘 要： | A series of nanocomposite thin films, composed of Nd2Fe14B and α-Fe, has been prepared by DC-magnetron sputtering combined ion beam sputtering onto Si (100) substrates. The effects of post annealing on the microstructure and magnetic properties of NdFeB/α-Fe/NdFeB]-type thin films have been investigated. The X-ray diffraction (XRD) study showed that annealing of the films for 30min at temperatures 550,600,650,700℃ resulted in the appearance of diffraction peaks, characteristic for Nd2Fe14B tetragonal structure, α-Fe and Nd2O3 phases. The investigation using the Vibrating Sample Magnetometer (VSM) with a maximum applied field of 2 T indicated that with the increase of the annealing temperature, the magnetic properties of the multilayer films were improved and reached peak value at 650℃ (Hci=41.72kA·m-1, Mr/Ms=0.4, (BH)max=30.35kJ·m-3), after which the magnetic properties were decreased greatly. Along with the increase of the thickness of α-Fe layer from Tα-Fe16nm, the coercivity Hci, saturation magnetization Ms, and remanence ratio Mr/Ms all declined. As the Atomic Force Microscope (AFM) indicated, after being annealed at 650℃ for 30min, the sample was showed fine surface morphology with grain size 60nm≤dα-Fe≤80nm and 100nm≤dNdFeB≤150nm.
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