In this work, the thermal properties of ternary Li3x
Co7–4x
Sb2+x
O12 solid solutions are
studied for different
concentrations in the range 0 ≤ x ≤
0.7. Samples are elaborated at four different sintering temperatures:
1100, 1150, 1200 and 1250 °C. The effect of increasing the content
of Li+ and Sb5+, accompanied by the reduction
of Co2+, on the thermal properties is studied. It is shown
that a thermal diffusivity gap, which is more pronounced for low values
of x, can be triggered at a certain threshold sintering
temperature (around 1150 °C in this study). This effect is explained
by the increase of contact area between adjacent grains. Nevertheless,
this effect is found to be less pronounced in the thermal conductivity.
Moreover, a new framework for heat diffusion in solids is presented
that establishes that both the heat flux and the thermal energy (or
heat) satisfy a diffusion equation and therefore highlights the importance
of thermal diffusivity in transient heat conduction phenomena.