Polar precursor ordering in BaTiO3 detected by resonant piezoelectric spectroscopy

An experimental method, Resonant Piezoelectric Spectroscopy (RPS), is introduced for the detection of polar precursor effects in ferroelectric and multiferroic materials. RPS is based on the excitation of elastic waves through the piezoelectric effect in a sample. As the intensity of these waves is significantly amplified through mechanical resonances, RPS is very sensitive to the development of polar nanostructures. Using RPS, we identify polar nanostructures in BaTiO3 as a precursor in the cubic phase. Results are compatible with polar tweed structures which persist up to 613 K. This temperature is much higher than previously reported.