Effects of Fe3O4underlayer on the annealing temperature of CoFe2O4thin films

✍ Scribed by Zhong, Zhiyong ;Zhang, Huaiwu ;Tang, Xiaoli ;Jing, Yulan ;Jia, Lijun ;Liu, Shuang

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 222 KB
• Volume: 206
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200824370

✦ Synopsis

Abstract

CoFe~2~O~4~ films of 100 nm thickness were deposited on 20 nm, rf magnetron‐sputtered Fe~3~O~4~ underlayers on naturally oxidized Si (100) substrates. These films were then annealed, and the magnetic properties and microstructures were investigated as a function of annealing temperature. Results show that the optimum annealing temperature to obtain the maximum coercivity decreases from 700 °C for films without Fe~3~O~4~ underlayers to 500 °C for films with underlayers. The decreased annealing temperature corresponds to a phase transformation of the Fe~3~O~4~ underlayers at about 400–500 °C, which accelerates the increase in grain size of the cobalt ferrite films. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)