磁场退火对FePt/Ag薄膜磁性能的影响

Effect of magnetic field annealing on the magnetic properties of FePt/Ag thin films

采用磁控溅射法室温沉积获得FePt/Ag薄膜,然后在500℃下,于真空磁退火炉中对薄膜进行退火处理。利用XRD和振动样品磁强计(VSM),研究了磁场退火对薄膜结构和磁性能的影响。结果表明,500℃零磁场退火获得了矫顽力为0.763 4 MA.m–1、平均晶粒尺寸21 nm的L10-FePt薄膜。磁场提供了FePt成核生长的驱动力,0.8 MA.m–1磁场退火后FePt的平均晶粒尺寸为26 nm,矫顽力增大至0.804 3 MA.m–1。非磁性Ag的掺杂可有效抑制磁性FePt晶粒的团聚生长。

FePt/Ag thin films were obtained by magnetron sputtering,and as-depostied films were annealed in vacuum magnetic annealing furnace at 500 ℃ with and without magnetic field.The structure and magnetic properties of the thin films were investigated with X-ray diffraction（XRD） and vibrating sample magnetometer（VSM）.Results show that L10-FePt thin film with coercive force value of 0.763 4 MA.m–1 and mean grain size of 21 nm is obtained after annealing at 500 ℃ without magnetic field.Magnetic filed of 0.8 MA.m–1 provides driving force for nucleation growth of FePt,so the mean grain size of FePt increases to 26 nm,and the coercive force value increases to 0.804 3 MA.m–1 after magnetic field annealing.While the doping of Ag suppresses effectively aggregation and growth of magnetic FePt grain.