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

Abstract

We report in situ manipulation of the in-plane strain εxx(BFMO) and coercive field EC(BFMO) of BiFe0.95Mn0.05O3 (BFMO) films epitaxially grown on La0.7Sr0.3MnO3 film buffered 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 (PMN-PT) substrates. PMN-PT poling-induced strain is effectively transferred to BiFe0.95Mn0.05O3 films and enhances εxx(BFMO) and EC(BFMO), with a gauge factor (ΔEC(BFMO)/EC(BFMO))/(δεxx) ∼−25 and −326 for the BFMO(001) and BFMO(111) films, respectively. Based on the strain dependence of EC(BFMO), we established a quantitative relationship between EC(BFMO) and εxx(BFMO). Using ferroelastic strain of PMN-PT, we achieved reversible and non-volatile modulation of strain and EC(BFMO) of BFMO films, providing an approach for non-volatile and reversible turning of strain and physical properties of ferroelectric films.