Exchange Bias in Polycrystalline BiFe1-xMnxO3/Ni81Fe19 Bilayers

• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2012,（9）
• 页码范围: 177-180
• 页数: 4页
• 语种: 英文
• DOI: 10.1088/0256-307X/29/9/097701

摘要

Polycrystalline BiFe1-xMnxO3 films with x up to 0.50 are prepared on LaNiO3 buffered surface oxidized Si substrates.The doped Mn is confirmed to be partially in a +4 valence state.A clear exchange bias effect is observed with a 3.6 nm Ni81Fe19 layer deposited on the top BiFe1-xMnx O3 layer,which decreases drastically with increasing Mn doping concentration and finally to zero when x is above 0.20.These results clearly demonstrate that the exchange bias field comes from the net spins due to the canted antiferromagnetic spin structure in polycrystalline BiFe1-xMnxO3 films,which transforms to a collinear antiferromagnetic spin structure when the Mn doping concentration is larger than 0.20.