Specific heat capacity cp(T) of the solid phase you'll find here:
http://webbook.nist.gov
If you need effective thermal transport properties like effective thermal diffusivity or effective thermal conductivity of a packed bed, gas phase and radiation properties play a significant role.
In my current project SolidHeat Kinetic, we measure effective thermal diffusivity and effective thermal conductivity of different metal oxide packed beds based on Laser Flash Analysis and Transient Hot Bridge method..