Vector imaging of electric field-induced reversible magnetization reversal in exchange-biased multiferroic heterostructures

交换偏置多铁异质结中电场调控可逆性磁化反转的矢量分析研究

Exchange bias between ferromagnetic and antiferromagnetic layers has been widely utilized in spintronic devices.Controlling the exchange bias in magnetic multilayers by an electric field(E-field)has been proposed as a low-power solution for manipulating the macroscopic properties such as exchange bias fields and magnetization values,while how the magnetic domains respond to the E-fields has rarely been reported in an exchange-biased system.Here,we realize the vector imaging of reversible electrical modulation of magnetization reversal in exchange-biased CoFeB/IrMn/PMN-PT(011)multiferroic heterostructures,utilizing in-situ quantitative magneto-optical Kerr effect(MOKE)microscopy.Under the electrical control,magnetic domains at-80 Oe rotate reversibly between around 160°and 80°-120°,whose transverse components reverse from 225°to 45°correspondingly.Moreover,pixel-by-pixel comparisons are conducted to further imply the reversible magnetization reversal by E-fields.Efield-induced reversible magnetization reversal is also demonstrated without applying external magnetic fields.Vector imaging of electrical manipulation of exchange bias is of great significance in understanding the magnetoelectric effect and the development of next-generation spintronic devices.

铁磁与反铁磁层间的交换偏置效应已在自旋电子器件中得到了广泛应用.目前,利用电场调控这一低能耗的方式已经实现了对交换偏置磁性多层膜中如交换偏置场和磁化值等宏观性质的调节.然而,交换偏置体系中磁畴如何随施加电场进行演化却鲜有报道.本文采用定量磁光克尔效应(MOKE)显微成像系统,实现了原位矢量分析CoFeB/IrMn/PMN-PT(011)交换偏置多铁异质结中电场作用下的可逆磁化反转.在保持偏置磁场于-80 Oe不变的情况下,外加电场驱动磁畴的磁化方向在160°方向与80°-120°方向区间内往复变化,对应磁畴的横向分量也于225°方向与45°方向间来回切换.同时,通过逐像素比对不同电场下的磁畴,进一步证实了电场调节磁化反转的可逆性.此外,在零偏置磁场下也实现了对磁化反转的可逆电场调节.电场调控交换偏置的矢量分析对于理解磁电效应以及发展下一代自旋电子器件具有重要意义.