Fabrication of High Performance Thick Film Magnets by Aerosol Deposition Method

1.目的在电机和电磁设备小型化的趋势下，对小厚度稀土磁体的需求越来越大。气溶胶沉积(AD)法是制备厚度在几μm到500μm之间的厚膜的理想方法之一，其沉积速度约为5-50μm/min，比传统的溅射方法快500-5000倍。因此，在本研究中，我们将该方法应用于高性能厚膜磁体的制备，并对其可能性进行了研究。结果(1)Sm-Fe-N AD膜的制备及其磁性：在玻璃衬底上制备的Sm-Fe-N AD膜，沉积10min后的厚度约为45μm，采用黄铜衬底沉积后，厚度可达190μm。沉积速率估计为15-19μm/m in。薄膜的剩磁(BR)为0.4T~0.6T，矫顽力(μ_0H&lt；Cj&gt；)为1.6T~1.8T，高于t…。更多的初级原粉。AD膜的微维氏硬度约为500-700。AD膜由α-Fe和Sm_2Fe_&lt；17&Gt；N_x相组成，晶粒度约为200-400μm，比初生粉小一个数量级。(2)各向异性Sm-Fe-N AD膜的制备：磁体或螺线管线圈使Sm-Fe-N的c轴有沿磁场取向的趋势。特别是在平面内施加0.19T的磁场时，测得的沿磁场方向的剩磁随磁场的增大而增大。(3)Fe_3B/Nd2Fe_(14)&Gt；B纳米复合AD膜的可能性：磁滞回线和X射线衍射分析表明，原始粉末是由Fe_3B和Nd2Fe_(？)14&Gt；B相组成的纳米复合粉末。原料粉的粒度越大(12.45μm)，沉积速率和膜厚越大。虽然沉积的AD膜由Fe3B和Nd2Fe&lt；14&gt；B相组成，但具有较高的剩磁和较低的矫顽力(H&lt；Cj&gt；=0.84Koe)。此外，Ar气氛中的退火进一步降低了样品的矫顽力。这些低的矫顽力被认为与Nd2Fe&lt；14&Gt；B相相对较低的各向异性场、AD方法中产生的缺陷以及α-Fe相的存在有关。较少

1. PurposeRare earth magnets with small thickness are strongly demanded in the trend of downsizing motors and electromagnetic devices. The aerosol deposition (AD) method is one of the attractive methods for the fabrication of thick films with thickness of several μm to 500 μm. The deposition rate is around 5-50 μm/min, which 500-5000 times faster than conventional sputtering method. Therefore, in this investigation, we applied this method for the fabrication of high performance thick film magnets and investigated its possibility.2. Results(1) Fabrication of Sm-Fe-N AD Films and their Magnetic Properties : Since the thickness of Sm-Fe-N AD films fabricated on glass substrate was around 45 μm after deposition of 10 min, the thickness reached to 190 μm after the deposition using brass substrate. The deposition rate was estimated as 15-19 μm/min. The films showed the remanence (Br) of 0.4-0.6 T and the coercivities (μ_0H_<cJ>) increased from 1.6-1.8 T. These coercivities were higher than t … More hat of primary raw powders. The microvickers hardness of the AD films was around 500-700. The AD films consisted of α-Fe and Sm_2Fe_<17>N_x phases and the grain size was around 200-400 μm, which was one order smaller than that of primary powders.(2) Fabrication of anisotropic Sm-Fe-N AD Films : It is concluded that the c-axis of Sm-Fe-N has a tendency to align along the magnetic field by using magnets or solenoid coils. Especially, applying magnetic fields of 0.19 T in plane, the remanence measured along the applied field increased with increasing the magnetic field. The maximum value of remanence was 0.54 T, which was 29% higher than that without the applied field (0.42 T).(3) Possibility of Fe_3B/Nd_2Fe_<14>B Nanocomposite AD Films : Hysteresis loop and XRD analysis revealed that the raw powders was nanocomposite powders consisted of Fe_3B and Nd_2Fe_<14>B phase. The larger powder size of raw powders (12.45 μm) influenced the deposition rate and film thickness. The as-deposited AD film exhibited high remanence but low coercivity (H_<cJ>=0.84 kOe), though the film consisted of the Fe_3B and Nd_2Fe_<14>B phases. In addition, the coercivity further decreased by the annealing in Ar. These low coercivities were considered to be related to the relatively low anisotropy field of Nd_2Fe_<14>B phase, the defects induced during the AD method and the presence of α-Fe phase. Less