Poisson's ratio of BiFeO_3 thin films: X-ray reciprocal space mapping under variable uniaxial strain

摘要

We investigate the mechanical properties of BiFeO_3 (BFO) thin films grown on SrTiO_3 (001) substrates that were manually bent using a specially designed uniaxial bending stage. X-ray measurements under variable uniaxial strain show that excessive strains up to ～2% could be applied along the [100] direction with little cross talk between [100] and [010] directions. X-ray reciprocal space maps were acquired to investigate the evolution of -a and c-axis lattice constants under variable strain and Poisson's ratio of BFO thin films v_(zx) was determined to be 0.30 ±0.01.