Nanoscale switching characteristics of nearly tetragonal BiFeO3 thin films.
We have investigated the nanoscale switching properties of strain-engineered BiFeO(3) thin films deposited on LaAlO(3) substrates using a combination of scanning probe techniques. Polarized Raman spectral analysis indicates that the nearly tetragonal films have monoclinic (Cc) rather than P4mm tetragonal symmetry. Through local switching-spectroscopy measurements and piezoresponse force microscopy, we provide clear evidence of ferroelectric switching of the tetragonal phase, but the polarization direction, and therefore its switching, deviates strongly from the expected (001) tetragonal axis. We also demonstrate a large and reversible, electrically driven structural phase transition from the tetragonal to the rhombohedral polymorph in this material, which is promising for a plethora of applications.
Mazumdar
Dipanjan
D
Center for Materials for Information Technology, University of Alabama, Tuscaloosa, Alabama 35487, USA.
Shelke
Vilas
V
Iliev
Milko
M
Jesse
Stephen
S
Kumar
Amit
A
Kalinin
Sergei V
SV
Baddorf
Arthur P
AP
Gupta
Arunava
A