Data for: The effect of second phase la0.67tio2.87 on the phase structure and impedance spectroscopy of La2Ti2(1 + x)O7 piezoelectric ceramics

The impedance spetra of La2Ti2(1 + x)O7 ceramicsLa₂Ti₂(1+x)O₇陶瓷的阻抗谱（impedance spectra）