Thickness-Dependent Ru Exchange Spring at La0.7Sr0.3MnO3–SrRuO3 Interface

Abstract

The conducting oxide ferromagnets SrRuO3 (SRO) and La0.7Sr0.3MnO3 (LSMO) form a Ru exchange spring at a coherent low-interdiffusion interface grown on TiO2-terminated SrTiO3(STO)(001) substrates as SRO(d)/LSMO/STO(001) bilayers. Field- and temperature-dependent magnetization data with systematically varied thickness d of SRO from 7 to 18 unit cells (uc) indicate a thickness of 10–14 uc of the exchange spring which governs magnetic switching and causes thickness-dependent field-cooling effects. Mn L3 edge X-ray magnetic circular dichroism (XMCD) data reveal the dominating in-plane orientation of interfacial spins. In low magnetic fields, noncoplanar, topologically nontrivial spin textures arise and can be switched, driven by the Zeeman energy of the LSMO layer.