Hello! Could someone please drop a link, a book name or an understandable explanation on what ionic conductivity in solids is? I am a 3rd year Applied Physics student and understand the basic concept, but a deeper description would be interesting for me: for example, how is resistance calculated, what would be characteristic times of ions hopping and so on. I have looked through a textbook by Kittel (Intro. to Solid State Ph., 8th edition), but did not find a satisfactory discussion. Thank you very much.