Modulation of exchange bias in La0.35Sr0.65MnO3/La0.7Sr0.3MnO3 through volatile polarization of P(VDF-TrFE) gate dielectric

Abstract

Electric-field regulation of magnetic properties in perovskite manganites has attracted much attention for its potential in spintronics. For antiferromagnetic perovskite manganites, fewer studies are reported due to technological difficulties in probing their magnetic properties. Here, negative exchange bias (EB) is realized in epitaxial antiferromagnetic/ferromagnetic manganite bilayers with atomically flat interfaces. The low-voltage pulse modulation of EB is demonstrated using the field-effect device geometry with the ferroelectric copolymer, polyvinylidene fluoride with trifluoroethylene as a dielectric gating layer, antiferromagnetic La0.35Sr0.65MnO3 (AF-LSMO) as pinning layer, and ferromagnetic La0.7Sr0.3MnO3 (FM-LSMO) as conduction channel. Instead of using non-volatile polarizations to control the EB, volatile polarizations in ferroelectric field effect transistors are suggested to be capable of modulating the EB. With high-resolution electron microscopy and spectroscopy, the non-volatile regulation of EB is attributed to the creation/annihilation of oxygen vacancies in the AF-LSMO layer via low-voltage pulses. This study reveals the effect of volatile electric polarizations in ferroelectric field effect devices and highlights the potential for low-voltage pulse control of the physical properties in antiferromagnetic perovskite oxide insulators.