Dumesnil K, Dufour C, Fernandez S, Oudich M, Avisou A, Rogalev A, Wilhelm F
Laboratoire de Physique des Matériaux (UMR CNRS 7556), Université H Poincaré-Nancy I, BP 239, 54506 Vandoeuvre les Nancy cedex, France.
J Phys Condens Matter. 2009 Jun 10;21(23):236002. doi: 10.1088/0953-8984/21/23/236002. Epub 2009 May 7.
The effect of the thermo-magnetic preparation on exchange bias is investigated in an exchange-coupled 3 nm DyFe(2)/12 nmYFe(2) superlattice. X-ray magnetic circular dichroism (XMCD) experiments at low temperature reveal that exchange bias originates from the quenched DyFe(2) magnetization, biasing the unpinned YFe(2) reversal. This quenched configuration can be tailored by changing the cooling field or the magnetic preparation at 300 K before zero-field cooling. Changing the amplitude of the cooling field induces interface domain walls and tends to modify the orientation of the pinning moments at the interfaces. This results in the observation of single loops and in the continuous variation of the bias field as a function of the cooling field. A specific magnetic preparation (field cycling) at 300 K induces different remanent states with lateral domains in the pinning layer, which remain unchanged at low temperature after zero-field cooling and behave independently. This gives rise to combined loops, whose shape reflects the domain populations.
在交换耦合的[3纳米DyFe₂/12纳米YFe₂]₂₂超晶格中研究了热磁制备对交换偏置的影响。低温下的X射线磁圆二色性（XMCD）实验表明，交换偏置源于淬灭的DyFe₂磁化强度，使未钉扎的YFe₂反转产生偏置。这种淬灭构型可以通过改变冷却场或在零场冷却之前在300K下进行磁制备来调整。改变冷却场的幅度会诱导界面畴壁，并倾向于改变界面处钉扎矩的取向。这导致观察到单回线，并且偏置场随冷却场连续变化。在300K下进行特定的磁制备（场循环）会在钉扎层中诱导出具有横向畴的不同剩余状态，这些状态在零场冷却后在低温下保持不变且独立存在。这产生了组合回线，其形状反映了畴的数量。
