The unique effect of in-plane anisotropic strain in the magnetization control by electric field

Abstract

The electric field control of magnetization in both (100)- and (011)-Pr0.7Sr0.3MnO3/Pb(Mg1/3Nb2/3)0.7Ti0.3O3(PSMO/PMN-PT) heterostructures were investigated. It was found that the in-plane isotropic strain induced by electric field only slightly reduces the magnetization at low temperature in (100)-PSMO/PMN-PT film. On the other hand, for (011)-PSMO/PMN-PT film, the in-plane anisotropic strain results in in-plane anisotropic, nonvolatile change of magnetization at low-temperature. The magnetization, remanence and coercivity along in-plane [100] direction are suppressed by the electric field while the ones along [01-1] direction are enhanced, which is ascribed to the extra effective magnetic anisotropy induced by the electric field via anisotropic piezostrains. More interestingly, such anisotropic modulation behaviors are nonvolatile, demonstrating a memory effect.

Magnetic Field Sensing by Exploiting Giant Nonstrain-Mediated Magnetodielectric Response in Epitaxial Composites

“…Recently, 2–2-type heteroepitaxial ME composite thin films have been extensively investigated due to their high ferroelectric and ferromagnetic properties, low leakage current, high quality interface between the ferroic phases, and control of the crystallographic orientation of each layer. − The strain-mediated direct ME coupling, implying magnetic field-induced piezoelectric potential, has been observed in various heteroepitaxial composites, including ferromagnetic La 1– x Sr x MnO 3 and ferroelectric oxides. ,, However, the lattice misfit strain along with the strong clamping effect from the substrate degrades both piezomagnetic and piezoelectric coefficients resulting in reduced strain-mediated ME coupling. Similarly, the strain-mediated converse ME effect, electric field-induced magnetic moment change, has been negligible in thin epitaxial ME composites, and interface charge-mediated ME coupling has mainly contributed toward modulating the magnetic moment of the ferromagnetic layer. − On the other hand, avoiding the substrate clamping effect between ferroic phases significantly enhanced the strain-mediated converse ME coupling in epitaxial ferromagnetic films grown on ferroelectric single-crystalline substrates. − Therefore, relaxation of the substrate clamping effect or development of nonstrain-mediated coupling dynamics are required for further improvement of the ME response of heteroepitaxial composites.…”

“…The initial magnetic properties of the LSMO films were found to degrade following PZT deposition. In prior reports, it has been shown that the modulation of the magnetic properties in an epitaxial ME composite results from interface charge-mediated converse ME coupling − and strain-mediated ME coupling across the ferroelectric/ferromagnetic interface. − In the case of interface charge-mediated converse ME coupling, the interfacial magnetization is changed due to electrostatic charge accumulation at the PZT/LSMO interface from ferroelectric spontaneous polarization. ,− Prior studies have shown that interfacial charge accumulation modulates the valence state of Mn from the high spin state Mn 3+ (S = 2) to the low spin state Mn 4+ (S = 3/2) near the interface. This results in an interfacial ferromagnetic to antiferromagnetic phase transition in the accumulation state and, thereby, changes the magnetic moment of LSMO.…”