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

In strongly correlated materials multiple electronic phases can form simultaneously in real space, offering the potential of devices with multiple electronic properties, if such phase separation can be controlled. Here, Li et al study this electronic phase separation in LaMnO3/CaMnO3/PrMnO3 superlattice, and find a nano-network electronic phase separation resulting from local strain relaxation that persists through thermal cycling. 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.

Automated summary

In strongly correlated materials, electronic phase separation can occur simultaneously in real space, and the ability to control this separation is crucial for designing devices with multiple electronic properties. Li et al studied the electronic phase separation in LaMnO3/CaMnO3/PrMnO3 superlattice and discovered a nano-network electronic phase separation resulting from local strain relaxation, which persisted through thermal cycling.