Effect of flash thermal annealing by pulsed current on rotational anisotropy in exchange-biased NiFe/FeMn film

• 来源期刊: 中国物理B（英文版）
• 关键词: rapid annealing sputtering pulsed current rotational anisotropy
• 年，卷（期）: 2018,（8）
• 页码范围: 553-558
• 页数: 6页
• 语种: 英文
• DOI: 10.1088/1674-1056/27/8/087504

摘要

In this paper, Ta/[NiFe(15 nm)/FeMn(10 nm)]/Ta exchange-biased bilayers are fabricated by magnetron sputtering, and their static and dynamic magnetic properties before and after rapid annealing treatment with pulsed current are charac-terized by using a vibrating sample magnetometer (VSM) and a vector network analyzer (VNA), respectively. The exchange bias field He and static anisotropy field Hstak decrease from 118.45 Oe (1 Oe=79.5775 A·m?1) and 126.84 Oe at 0 V to 94.75 Oe and 102.31 Oe at 90 V, respectively, with increasing capacitor voltage, which supplies pulsed current to heat the sample. The effect of flash thermal annealing by pulsed current on the rotational anisotropy (Hrot), the difference value between static and dynamic magnetic anisotropy, is investigated particularly. The highest Hrot is obtained in the sample annealing with 45-V capacitor (3300 μF) voltage. According to the anisotropic magnetoresistance measurements, it can be explained by the fact that the temperature of the sample is around the blocking temperature of the exchange bias system (Tb) at 45 V, the critical temperature where the formation of more unstable antiferromagnetic grains occurs.