 Thermal diffusivity

Thermal diffusivity is $\kappa =k/(\rho c_p)$, the ratio of thermal conductivity to volumetric heat capacity. It sets the diffusion length $\sqrt{\kappa t}$ over time $t$.

Thermal diffusivity is a material property that indicates how quickly heat can spread through a material. It is defined as the ratio of thermal conductivity to the product of density and specific heat capacity.