Magnetic-field effect in the heterostructure Ba$_{0.8}$Sr$_{0.2}$TiO$_3$/LaMnO$_3$

TL;DR

This study investigates how an external magnetic field influences the magnetotransport properties of a Ba$_{0.8}$Sr$_{0.2}$TiO$_3$/LaMnO$_3$ heterostructure, revealing magnetic-field-induced changes in interface ferromagnetism and resistance.

Contribution

It demonstrates the magnetic-field dependence of interface ferromagnetism and resistance in a heterostructure with a two-dimensional electron gas at the interface.

Findings

External magnetic field decreases heterostructure resistance.

Magnetic cycling increases ferromagnetic regions at the interface.

Resistance changes are linked to ferromagnetic order development.

Abstract

We have studied transport and magnetotransport properties of the heterostructure consisting of the ferroelectric Ba$_{0.8}$Sr$_{0.2}$TiO$_3$ film deposited on the single crystalline manganite LaMnO$_3$. Two-dimensional electron gas arising at the interface transforms the interface region of the antiferromagnetic manganite to the ferromagnetic state with the reoriented magnetic moments. We obtained that the contribution of these ferromagnetic regions to the resistance of the heterostructure appears to be dependent on the external magnetic field applied perpendicularly to the interface (and parallel to {\it c}-axis of the ferromagnetic state of LaMnO$_3$). We believe that the decrease of the resistance of the studied heterostructure under the influence of the external magnetic field is caused by an appearance of the ferromagnetic order in the interface area. This leads to a relatively small resistance. In turn, the cycling of the applied magnetic field leads to the increase of the regions of the ferromagnetic order and, as a result, to decreasing scattering of the current carriers at the ferromagnetic disordering.