Effects of thermal strain on electric properties of lead zirconate titanate thin films upon LaNiO3 coated base metal plates

Abstract Electric properties for ferroelectric lead zirconate titanate (PZT50/50, 45/55, 40/60, 30/70) thin films on base metal plates with different thermal expansion coefficient (TEC) were calculated by a phenomenological model. Results show that when the TEC of substrates increases, dielectric constant, tunability and piezoelectric coefficient d33 of all PZT thin films with tetragonal phase are decreased due to the larger compressive thermal strain. PZT50/50 thin films deposited on smaller TEC substrates can achieve higher dielectric constant, tunability and d33. The computed dielectric constant of PZT50/50 thin films is in accordance with the measured results from sol-gel experimental process, and the trend of dielectric constant of PZT films adjacent to morphotropic phase boundary (MPB) derived from some references also agrees with that from calculation. These results suggest that higher tunability and d33 of PZT films can be obtained by choosing smaller TEC substrates.