Intrinsic uniaxial stress induced by co-doping and its influence on piezoelectric performance of PbZr0.45Ti0.55O3 ferroelectric

Intrinsic uniaxial stress along the [001]pc (pseudo-cubic [001]) direction in tetragonal PbZr0.45Ti0.55O3 polycrystal is obtained via A-site acceptor-donor (Li+-Al3+) co-doping. In-situ X-ray diffraction results demonstrate that local A-site cations ordering of donor-acceptor (along the [001]pc direction) should be responsible for the intrinsic uniaxial stress. The diffuse tetragonal-cubic phase transition and enhanced piezoelectricity are achieved in the doped ferroelectric. Based on the phenomenological theory, enhanced piezoelectricity is related to local low symmetry and stress-driven flattening of free-energy profile. The present study provides a promising method to obtain intrinsic uniaxial stress in Pb(TiZr)O3 polycrystal via donor-acceptor co-doping, and reveal the relationship between this doping route, chemical stress and corresponding properties.