Exchange Bias in Polycrystalline BiFe 1- x Mn x O 3 /Ni 81 Fe 19 Bilayers
Exchange Bias in Polycrystalline BiFe 1- x Mn x O 3 /Ni 81 Fe 19 Bilayers
复制标题
DOI：
10.1088/0256-307x/29/9/097701
复制
发表时间：
2012-09
影响因子：
3.5
通讯作者：
Xueyong Yuan;X. Xue;Lifang Si;J. Du;Qingyu Xu
中科院分区：
文献类型：
--
作者：
Xueyong Yuan;X. Xue;Lifang Si;J. Du;Qingyu Xu
在LaNiO_3缓冲表面氧化硅衬底上制备了x高达0.50的BiFe1-−-xMnxO_3多晶薄膜。证实了掺杂后的Mn部分处于+4价态。在BiFe_1-−_xMn_xO_3的顶层上沉积了一层3.6nmNi81Fe19，观察到了明显的交换偏置效应，随着掺杂浓度的增加，交换偏置效应急剧减小，当x>0.20时，偏置效应趋于零。这些结果清楚地表明，在多晶BiFe1-−-xMnxO_3薄膜中，交换偏置场来自于由于倾斜的反铁磁自旋结构而产生的净自旋，当Mn掺杂浓度大于0.20时，该自旋结构转变为共线反铁磁自旋结构。
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−xMnxO3 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.