Ferromagnetic Domain Dynamics in Hole-doped Manganite Microstructures

The hole-doped manganite (La_0.5Pr_0.5)_0.67Ca_0.33MnO₃ (LPCMO) shows electronic phase separation among the ferromagnetic metallic (FMM) and anti-ferromagnetic insulating (AFM) regions. Such electronic phase separation leads to electric-field-induced movement of FMM regions, making hole-doped manganites promising candidates for applications in solid-state magnetic memory devices, such as racetrack memory. This work investigates the magnetic properties of LPCMO microstructures, particularly the magnetization reversal mechanism. We fabricated 20 x 120 µm² microstructures out of 30 nm-thick LPCMO films grown on (110) NdGaO₃ using pulsed laser deposition. We measured the magnetotransport properties of these wires using in-plane magnetic fields (H) applied at various angles (θ) to the applied voltage/current. Our results show that properties such as in-plane magnetic anisotropy and the magnitude of coercive fields (H_C) are unaffected in the LPCMO microstructures. However, H_C versus θ plots show that the domain reversal mechanism follows the modified Kondorsky model and that the microstructures have smaller saturation magnetization values in comparison to bulk (unpatterned) films. We also did not observe a significant electric field effect on the reversal mechanism for this specific composition of LPCMO. In the future, we plan to make narrower devices to get the sample size closer to the FMM domain size.