Open AccessRoom-temperature ferromagnetism observed in Si-Al2O3 composite film
Author(s) -
Zheng Yu-Long,
Zhen Cong-Mian,
Lei Ma,
Xiuling Li,
Pan Cheng-fu,
Denglu Hou
Publication year - 2011
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.60.117502
Subject(s) - ferromagnetism , materials science , amorphous solid , condensed matter physics , composite number , magnetism , coupling (piping) , composite material , crystallography , chemistry , physics
Room-temperature ferromagnetism (FM) is observed in Si-Al2O3 amorphous composite film. The magnetic moment is the highest in the case of the Si-Al2O3 composite films with the Si content being 15 vol.%, and distinct domains are detected in our films. The difference in magnetism property between sample annealed in Ar atmosphere and untreated composite film indicates that the observed ferromagnetism does not originate primarily from oxygen defects. It is concluded that the ferromagnetism arises from the direct coupling between defects. These defects orignate from the interface between Si particles and Al2O3 matrix. By varying the Si content in the film, one can change the defect density and thereby control the strength of the ferromagnetic coupling.