Electrocaloric properties of K(Ta0.6Nb0.4)O3/SrTiO3 double layer thin films using metal alkoxides

Abstract

In this study, KTN/STO thin films were fabricated on Pt/Ti/SiO2/Si substrate, as a buffer layer, and their structural and electrical properties were measured according to the number of STO coatings and investigated its applicability to electrocaloric materials. KTN/STO thin films showed a polycrystalline KTN XRD peaks with a pyrochlore phase. However, dependence on the number of STO coatings and pyrochlore phase was not observed. The average grain size was about 80 similar to 90 nm, the average thickness of 6-coated KTN thin film was about 320 nm, and the average thickness of the STO thin film coated once was about 50-55 nm. Saturation polarization of K(Ta0.6Nb0.4)O-3/SrTiO3 thin films was 24.5 mu C/cm(2). Electrocaloric temperature change Delta T of K(Ta0.6Nb0.4)O-3 thin film showed the maximum value of 3.14 degrees C at around 76 degrees C under a high electric field of 332.9 kV/cm.