In-situ X-ray diffraction study of stress-induced phase transition of (1 − x)BaZr0.2Ti0.8O3–xBa0.7Ca0.3TiO3 in polymer matrix composite

•The in-situ X-ray diffraction was studied on BZT–xBCT during tensile process.•Stress-induced phase transition of BZT–xBCT was observed during tensile process.•R → T phase transition may be the decisive factor for the huge d33 of BZT–xBCT.

Phase transitions of (1 − x)BaZr0.2Ti0.8O3–xBa0.7Ca0.3TiO3 (BZT–xBCT) powders under tensile stress were investigated using in-situ X-ray diffraction (XRD). Uniaxial stress was applied to the designed BZT–xBCT/polyimide composite films during XRD. Under stress, the rhombohedral (R) phase was found to transform into a tetragonal (T) phase, while the [001] direction of the T phase tends to be parallel to the tensile direction. T → R phase transition was not observed in the films upon tensile stress loading, implying that R → T phase transitions may be the decisive factor for the huge piezoelectric response of the BZT–xBCT system.