  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.
