Temperature dependent spin dynamics in La0.67Sr0.33MnO3/Pt bilayers

Complex ferromagnetic oxides such as La_0.67Sr_0.33MnO₃ (LSMO) offer pathways for creating energy-efficient spintronic devices with new functionalities. LSMO exhibits high-temperature ferromagnetism, half metallicity, sharp resonance linewidth, low damping, and a large anisotropic magnetoresistance response. Combined with Pt, a proven material with high spin-charge conversion efficiency, LSMO can be used to create robust nano-oscillators for neuromorphic computing. Ferromagnetic resonance (FMR) and device-level spin-pumping FMR measurements are performed to investigate the magnetization dynamics and spin transport in NdGaO₃(110)/LSMO(15 nm)/Pt(0 and 5 nm) thin films ranging from 300 K to 90 K and compare the device performance with Py(7 nm)/Pt(5 nm) sample. The spin current pumped into Pt is quantified to determine the temperature-dependent influence of interfacial interactions. The generated spin current in the micro-device is maximum at 170 K for the optimally grown LSMO/Pt films. Additionally, this bilayer system exhibits low magnetic Gilbert damping (0.002), small linewidth (12 Oe), and a large spin Hall angle (≈3.2%) at 170 K. Ex situ deposited LSMO/Pt bilayers demonstrate excellent dynamic response, exhibiting fourfold enhancement in signal output, eightfold reduction in damping, and a threefold reduction in linewidth as compared to the Pt/Py system. Such robust device-level performance can pave way for energy-efficient spintronic-based devices.