Spin re-orientation induced anisotropic magnetoresistance switching in LaCo\(_{0.5}\)Ni\(_{0.5}\)O\(_{3-\delta}\) thin films

• Published in: arXiv.org 2023-04
• Main Authors: Sreejith, P K, Suraj, T S, Hari Babu Vasili, Sreya, Suresh, Gargiani, Pierluigi, Sethupathi, K, Cespedes, Oscar, Sankaranarayanan, V, Rao, M S Ramachandra
• Format: Article
• Language: English
• Subjects: Charge transfer; Electron transport; Ferromagnetic materials; Magnetic transitions; Magnetism; Magnetization; Magnetoresistance; Magnetoresistivity; Perovskites; Photoelectrons; Switching; Thin films; Transition temperature; Transport properties; Tuning
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2210.09608

Realization of novel functionalities by tuning magnetic interactions in rare earth perovskite oxide thin films opens up exciting technological prospects. Strain-induced tuning of magnetic interactions in rare earth cobaltates and nickelates is of central importance due to their versatility in electronic transport properties. Here we reported the spin re-orientation induced switching of anisotropic magnetoresistance (AMR) and its tunability with strain in epitaxial LaCo\(_{0.5}\)Ni\(_{0.5}\)O\(_{3-\delta}\) thin films across the ferromagnetic transition. Moreover, with strain tuning, we could observe a two-fold to four-fold symmetry crossover in AMR across the magnetic transition temperature. The magnetization measurements revealed an onset of ferromagnetic transition around 50 K, and a further reduction in temperature showed a subtle change in the magnetization dynamics, which reduced the ferromagnetic long-range ordering and introduced glassiness in the system. X-ray absorption and X-ray magnetic circular dichroism spectroscopy measurements over Co and Ni L edges revealed the Co spin state transition below the magnetic transition temperature leading to the AMR switching and also the presence of Ni\(^{2+}\) and Co\(^{4+}\) ions evidencing the charge transfer from Ni to Co ions. Our work demonstrated the tunability of magnetic interactions mediated electronic transport in cobaltate-nickelate thin films, which is relevant in understanding Ni-Co interactions in oxides for their technological applications such as in AMR sensors.