Intrinsic and quantitative effects of in-plane strain on ferroelectric properties of Mn-doped BiFeO3 epitaxial films by in situ inducing strain in substrates

We report in situ manipulation of the in-plane strain epsilon(xx(BFMO)) and coercive field E-C(BFMO) of BiFe0.95Mn0.05O3 (BFMO) films epitaxially grown on La0.7Sr0.3MnO3 film buffered 0.71Pb(Mg1/3Nb2/3)O-3-0.29PbTiO(3) (PMN-PT) substrates. PMN-PT poling-induced strain is effectively transferred to BiFe0.95Mn0.05O3 films and enhances epsilon(xx(BFMO)) and E-C(BFMO), with a gauge factor (Delta E-C(BFMO)/E-C(BFMO))/(delta epsilon(xx)) similar to -25 and -26 for the BFMO(001) and BFMO(111) films, respectively. Based on the strain dependence of E-C(BFMO), we established a quantitative relationship between E-C(BFMO) and epsilon(xx(BFMO)). Using ferroelastic strain of PMN-PT, we achieved reversible and non-volatile modulation of strain and E-C(BFMO) of BFMO films, providing an approach for non-volatile and reversible turning of strain and physical properties of ferroelectric films. (C) 2014 AIP Publishing LLC.