Perpendicular magnetic anisotropy in conducting <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>NiCo</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:mrow></mml:math> films from spin-lattice coupling
Corbyn Mellinger, Jace Waybright, Xiaozhe Zhang, Caleb M. Schmidt, Xiaoshan Xu
Abstract
High perpendicular magnetic anisotropy (PMA), a property needed for nanoscale spintronic applications, is rare in oxide conductors. We report the observation of a PMA up to 0.23 MJ/${\mathrm{m}}^{3}$ in modestly strained (--0.3%) epitaxial ${\mathrm{NiCo}}_{2}{\mathrm{O}}_{4}$ films which are room-temperature ferrimagnetic conductors. Spin-lattice coupling manifested as magnetoelastic effect was found as the origin of the PMA. The in-plane ${x}^{2}\text{\ensuremath{-}}{y}^{2}$ states of Co on tetrahedral sites play crucial role in the magnetic anisotropy and spin-lattice coupling with an energy scale of 1 meV/f.u. The elucidation of the microscopic origin paves a way for engineering oxide conductors for PMA using metal/oxygen hybridizations.