Question

state any diffusion between solid with solid

Answer 1

writing with chalk on the blackboard is a diffusion of solid solid

Answer 2

Diffusion can take place in gases, liquids, or solids. In solids, particularly, diffusion occurs due to thermally-activated random motion of atoms - unless the material is at absolute zero temperature (zero Kelvin), individual atoms keep vibrating and eventually move within the material. One of the possible net effects of diffusion is that atoms move from regions of high concentration of one element to regions with low concentration, until the concentration is equal throughout the sample.