Anomalous magnetic Properties of an iron film System deposited on fracture surfaces of α-Al2O3 ceramics

• 来源期刊: 中国物理B（英文版）
• 关键词: iron film ceramics exchange interactions magnetic measurements
• 年，卷（期）: 2008,（9）
• 页码范围: 3499-3504
• 页数: 6页
• 语种: 英文

摘要

An iron film percolation system is fabricated by vapour-phase deposition on fracture surfaces of α-Al2O3 ceramics.The zero-field-cooled(ZFC)and field-cooled(FC)magnetization measurement reveals that the magnetic phase of the film samples evolve from a high-temperature ferromagnetic state to a low-temperature spin-glass-fike state.which is also demonstrated by the temperature-dependent ac susceptibility of the iron films.The temperature dependence of the exchange bias field He of the iron film exhibits a minimum peak around the temperature T=5 K,which is independent of the magnitude of the cooling field Hcf.However,for T>10 K,(1)He is always negative when Hcf=2 kOe and(2) for Hcf=20kOe(1Oe≈80A/m),He changes from negative to positive values as T increases.Our experimental results show that the anomalous hysteresis properties mainly result from the oxide surfaces of the films with spin-glass-like phase.