Escalated Phase Separation Driven Enhanced Magnetoresistance in Manganite/Iridate Epitaxial Heterostructures

Phase separation in manganites leads to unique magnetic and electronic properties. 50% Ca-doped LaMnO₃ (LCMO), at the boundary of ferromagnetic (FM) and antiferromagnetic (AFM) states in La_1-xCa_xMnO₃ (0 ≤ x ≤ 1), is an ideal system to study phase separation behavior. Here, we have investigated the effect of a 5<i>d</i>-metal perovskite SrIrO₃(SIO) on the phase separation, magnetic, and magnetoresistance (MR) properties of LCMO. The MR, and colossal magnetoresistance (CMR), observed in LCMO/SIO bilayers were two orders and an order of magnitude (in %) larger, respectively than that in the single-layer film. We found the coexistence of FM and AFM/CO phases was responsible for the CMR and MR enhancement in the LCMO/SIO bilayer, pointing towards the importance of the phase separation and competition of both the individual materials in enhancing their magnetic and electronic properties.