J Mater Sci Technol ›› 2003, Vol. 19 ›› Issue (05): 491-494.

• Research Articles • Previous Articles     Next Articles

Reduction of Coercivity of Fe-N Soft Magnetic Film by Heat Treatment

Dan LI, Yousong GU, Xiangrong CHANG, Fushen LI, Lijie QIAO, Zhongzhuo TIAN   

  1. Department of Materials Physics, University of Science & Technology Beijing, Beijing 100083, China
  • Received:1900-01-01 Revised:1900-01-01 Online:2003-09-28 Published:2009-10-10
  • Contact: Dan LI

Abstract: 200 nm thick Fe-N magnetic thin films were deposited on glass substrates by RF sputtering. The as-deposited films have high saturation magnetization but their coercivity is also higher than what is needed Therefore it is very important to reduce coercivity. The samples were vacuum annealed at 250 °C under 12000 A/m magnetic field. When the N content was in the range of 5~7 at.pct, the thin films consisted of α'+α'' after heat treatment and had excellent soft magnetic properties of 4πM2=2.4 T, Hc<80 A/m. However, the thickness of a recording head was 2 μm, and Hc increased as thickness increased. In order to reduce the Hc, the sputtering power was raised from 200 W to 1000 W to reduce the grain size. 2 μm Fe-N thin films were vacuum annealed under the same condition, when the N content was in the range of 5.9~8.5 at.pct, the thin films kept its excellent magnetic properties of 4πM2=2.2 T, Hc<80 A/m. The properties of the films meet the need of a recording head material used in the dual-element GMR/inductive heads.

Key words: Fe-N, Soft magnetic film, Coercivity