Microstructural control and tuning of thermal conductivity in La0.67Ca0.33MnO3±δ

Manganites are one of only a small number of material families currently being trialled as room-temperature magnetic refrigerants. Here we examine the dependence of the thermal conductivity, κ, of La0.67Ca0.33MnO3±δ as a function of density, grain size and silver impregnation around room temperature. We use a simple effective medium model to extract relevant trends in the data and demonstrate a 3-fold increase in thermal conductivity by silver impregnation.