  Manipulating the strain induced poly-domains and phase transition in
correlated oxide material are important for high performance devices
fabrication. Though the electronic transport in the strained oxide film at
macroscopic scales can be directly measured, the anisotropic electronic state
and the controllable phase separation cross the insulator-to-metal transition
within nanoscale size are still elusive. Here, we selected VO2 crystal film as
a prototypical oxide and achieved the manipulation of anisotropy electronic
phase separation via injecting He+ nanobeam into VO2 film at room temperature.
In addition, this nanoscale phase separation was directly visualized by
infrared near-field imaging measurements, showing the pronounced and unique
cR-axis dependent anisotropy on VO2 surface. Our results offered new insights
towards understanding the anisotropic nanoscale phase separation in strained
metal oxide films.
