Prebreakdown state and its diagnostics in multilayer 0.55Pb-Mg$_{1/3}$Nb$_{2/3}$O$_{3}$–0.45PbSc$_{1/2}$ Nb$_{1/2}$O$_{3}$ compounds

Detection of breakdown voltage and diagnostics of the pre-breakdown state of a material is a topical task of studying the characteristics of dielectric materials and structures on their base under applied external electric field. A new efficient method for diagnosing the pre-breakdown state of multilayer structures (MLC) based on the 0.55Pb-Mg$_{1/3}$Nb$_{2/3}$O$_{3}$–0.45PbSc$_{1/2}$ Nb$_{1/2}$O$_{3}$ (PMN-PSN) ferroelectric relaxor is considered. The method is based on the analysis of the dynamics of the MLC surface temperature changes upon application of an external electric field. A set of MLC samples was tested under the action of an electric field $E$ = 10 – 120 kV/cm at temperatures from room temperature to 80$^\circ$. The critical electric field value characterizing the pre-breakdown state and, consequently, limiting the upper level of operating voltages for electrocaloric applications, was determined for PMN-PSN multilayer structures.