Electronically phase separated nano-network in antiferromagnetic insulating LaMnO3/PrMnO3/CaMnO3 tricolor superlattice

TL;DR

This study demonstrates the formation and control of an electronically phase separated nanoscale network in a layered manganite superlattice, revealing a direct link between magnetic and electronic states, and enabling potential device applications.

Contribution

It reports the creation of a controllable EPS nano-network in a manganite superlattice, showing the direct correlation between magnetic and electronic phases, and advancing manipulation techniques.

Findings

EPS nano-network is formed due to strain relaxation.

The network pattern is reproducible with temperature cycling.

Magnetic and transport states are directly correlated in EPS domains.

Abstract

Strongly correlated materials often exhibit an electronic phase separation (EPS) phenomena whose domain pattern is random in nature. The ability to control the spatial arrangement of the electronic phases at microscopic scales is highly desirable for tailoring their macroscopic properties and/or designing novel electronic devices. Here we report the formation of EPS nanoscale network in a mono-atomically stacked LaMnO3/CaMnO3/PrMnO3 superlattice grown on SrTiO3 (STO) (001) substrate, which is known to have an antiferromagnetic (AFM) insulating ground state. The EPS nano-network is a consequence of an internal strain relaxation triggered by the structural domain formation of the underlying STO substrate at low temperatures. The same nanoscale network pattern can be reproduced upon temperature cycling allowing us to employ different local imaging techniques to directly compare the magnetic and transport state of a single EPS domain. Our results confirm the one-to-one correspondence between ferromagnetic (AFM) to metallic (insulating) state in manganite. It also represents a significant step in a paradigm shift from passively characterizing EPS in strongly correlated systems to actively engaging in its manipulation.