Electric Field Effects on the Domain Reversal Mechanisms in Manganite Microstructures

(La_1-yPr_y)_1-xCa_xMnO₃ (LPCMO) displays multiple electronic phases that coexist and compete with each other, with the ferromagnetic metallic (FMM) phase and the charge ordered insulating (COI) phase being of particular interest in this study. Additionally, the anisotropic strain in thin films of LPCMO grown on a (110) NdGaO₃ (NGO) substrates leads to uniaxial in-plane magnetic anisotropy with a magnetic easy axis along the [1-10] direction and a hard axis along the [001] direction. Together, the phase coexistence and magnetic anisotropy may allow electric field driven tuning of the magnetic properties of LPCMO. Here we investigate the electric field effect on the domain reversal mechanism of (La_0.4Pr_0.6)_0.67Ca_0.33MnO₃ (LP6CMO) constrained to a volume on the same scale as the FMM domains. We measured the magnetoresistance (MR) of micrometer scale Hall bars of LP6CMO with channel dimensions 120 µm x 20 µm and 240 µm x 40 µm, and a film thickness of 120 nm. Resistance vs. in-plane magnetic field (H) plots revealed coercive fields (H_c) similar to values measured in unpatterned thin films. We varied the angle θ between H and the applied voltage/current through the Hall bars to generate H_c vs θ plots, which suggest domain switching through nucleation and growth. Fits to the modified Kondorsky model show a voltage dependence of the domain reversal mechanism and a suppressed saturation magnetisation in LP6CMO microstructures.