Effective thermal conductivity of SrBi4Ti4O15-La0.7Sr0.3MnO3 oxide composite: Role of particle size and interface thermal resistance

We present a novel approach to reduce the thermal conductivity ($\kappa$) in thermoelectric composite materials using acoustic impedance mismatch and Debye model. Also, correlation between interface resistance (R$_{int}$) particle size of dispersed phase on k is discussed. In particular, $\kappa$ an oxide which consists natural superlattice Aurivillius (SrBi$_4$Ti$_4$O$_{15}$) as matrix perovskite (La$_{0.7}$Sr$_{0.3}$MnO$_3$) investigated. A significant reduction composite, even lower than when La$_{0.7}$Sr$_{0.3}$MnO$_3$ smaller Kapitza radius (a$_K$) observed, depicting that R$_{int}$ dominates for a$_K$ due increased surface volume ratio. The obtained results have potential provide new directions engineering systems with desired promising field energy harvesting.