Temperature dependence of effective thermal conductivity and effective thermal diffusivity of Ni-Zn ferrites

Abstract

Measurement of thermal transport properties of nanocomposites of Ni-Zn ferrite in a copolymer matrix of aniline-formaldehyde has been made using transient plane source (TPS) technique. In the temperature range from room temperature to 140 °C both effective thermal conductivity ( λ e) and effective thermal diffusivity ( χ e) increase with increase in temperature and become maximum at a particular temperature which is a characteristic temperature for a given material. For further increase of temperature the λ e and χ e decreases slowly. An effect has also been made to predict theoretically these values by an empirical model. Addition of zinc concentration in the composite decreases the value of λ e and χ e over the entire range of temperature under investigation. It has also been found that the temperature at which a structural and bond strength change occurs depends on zinc concentration.