NiFe层溅射气压对顶部钉扎NiFe/FeMn薄膜静态磁性能的影响

用直流磁控溅射制备了系列Ta/NiFe/FeMn/Ta薄膜样品。利用振动样品磁强计(VSM)、X射线衍射(XRD)等手段研究了溅射气压对NiFe层交换偏置场、矫顽力、截止温度的影响。结果表明,交换偏置场随NiFe层溅射气压和NiFe层厚度的增加均减小;在较低的NiFe层溅射气压下,可以获得具有较高交换偏置场He和较低矫顽力Hc的样品;截止温度Tb随着NiFe层溅射气压的减小而增高。通过对比研究0.8Pa、0.4Pa、0.2PaNiFe层溅射气压下NiFe/FeMn薄膜的静态磁性及微结构变化,发现以上现象是由于在较低的溅射气压能够获得较好织构的NiFe(111),进而诱导出较好取向的FeMn(111)。取向良好的NiFe/FeMn薄膜产生较大的交换偏置场和较小的矫顽力及更高的截止温度。

Effects of NiFe sputtering pressure on the static magnetic properties of top-pinned NiFe/FeMn Films

Series of Ta/NiFe/FeMn/Ta samples were prepared by DC magnetron sputtering. The effects of different NiFe sputtering pressure on the exchange bias field He, coercive field Hc and blocking temperature Tb of Ta/NiFe/FeMn/Ta films were studied in this paper. The results reveal that He increase with increasing NiFe sputtering pressure or NiFe thickness. At lower NiFe sputtering pressure, the sample with higher He and lower Hc can be obtained. The blocking temperature Tb increases with increasing NiFe sputtering pressure. Through comparative study on the static magnectic properties of samples sputtered at spurting pressure of 0.8 Pa, 0.4 Pa and 0.2 Pa, it was found that well textured NiFe (111) thus higher oriented FeMn (111) can be obtained at lower spurting pressure. Well oriented NiFe (111)/FeMn (111) films yielded the higher exchange anisotropy field, lower coercivity, and higher blocking temperature.