论文标题:Nd-Fe-B/α-Fe两相纳米晶复合交换永磁薄膜结构和磁性研究
Preparation and Property Investigation of Secondarily Intercalated Montmorillonite/Polystyrene Nanocomposite
论文作者 孙泓
论文导师 胡社军,论文学位 硕士,论文专业 材料加工工程
论文单位 广东工业大学,点击次数 190,论文页数 89页File Size5133k
2003-05-01论文网 http://www.lw23.com/lunwen_37168597/ 纳米晶;交换耦合;稀土永磁
nanocrystalline;exchange coupling;rare-earth permanent magnets
用射频磁控溅射技术制备了由硬磁相Nd_2Fe_(14)B和软磁相α-Fe组成的纳米复合多层膜，研究了多层膜微结构和退火温度对Nd_2Fe_(14)B/α-Fe复合多层膜的表面形貌和磁性能的影响；用X射线衍射仪分析了复合多层膜的相结构；用电子探针和俄歇能谱仪分析了复合多层膜的成分；用扫描电镜观测了复合多层膜的表面形貌；用振动样品磁强计测试了复合多层膜的磁性能。研究结果表明： 用RFMS-4射频磁控溅射仪制备纳米复合多层膜技术稳定可靠，在优化工艺条件下能保证薄膜成分和溅射速率的稳定性。 制备出[NdFeB(15nm)/α-Fe (x)]_(10)(x=0，5，10，15nm)和[NdFeB (y)/α-Fe (5nm)]_(10(20))(y=5，25nm)系列复合多层膜，在不同退火温度(550℃，600℃，650℃，700℃)下进行热处理。发现随着α-Fe所占体积百分比增加，多层膜的矫顽力下降，剩余磁化强度提高，最大磁能积增加，当α-Fe层的体积达到50％的时，复合多层膜具有最大磁能积。在650℃退火后，调制结构为[NdFeB(5nm)/α-Fe(5nm)]_(20)复合多层膜，在室温下可获得的最佳磁性能：矫顽力 _iH_c=148.9kA/m，剩余磁化强度M_r=264.1kA/m，剩磁比M_r/M_s=61％，最大磁能积(BH)_(max)=42kJ/m~3。
The multilayer films composed of hard-magnetic phase Nd-Fe-B and soft- magnetic phase a-Fe were deposited by RF magnetron sputtering. The effect of the annealing temperature and the structure of multilayer on the surface morphology and magnetic properties of discontinuous Nd-Fe-B/ a-Fe multilayer films were investigated. Magnetic properties of the discontinuous multilayer films were measured with Vibration Sample Magnetometer (VSM) respectively. The phase structure of the films was determined by X-ray Diffraction (XRD). The component of the films was analyzed by Energy Spectrometer(EDS) and Auger Electron Spectroscopy (AES). The surface morphology of the films were observed by Scan Electron Microscope (SEM) respectively. The result showed that:The technical characteristic of RFMS-4 sputtering apparatus in depositing nanometer multilayer film is stable. The concentration and deposition rate of the films are controllable with the optimization parameters on the RFMS-4 sputtering apparatus.For the [NdFeB(15nm)/ α-Fe (x)]10 (x=0,5,10,15nm) and [NdFeB(y)/ α-Fe (5nm)]10(20)(y=5,25nm) multilayer films annealed at 550℃, 600℃, 650℃, 700℃, It is found that coercive force decreases, but remanence and energy product increase with increasing a-Fe volume percentum. The multilayer films has the most energy product when a-Fe volume percentum is 50%. The structure [NdFeB(5nm)/a-Fe(5nm)]2o multilayer films annealed at 650 ℃ has the highest magnetic property: coercive force iHc=148.9kAJm, remanence Mr=264.1kA/m, remanence radio Mr/Ms=61 %, maximal energy product (BH)max = 42kJ/m3.
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