Complex sentence: After the war he moved to the University of Bristol Physics Department to do research in solid state physics but switched to research on crystal dislocation and his work with Burton and Cabrera was to demonstrate the role dislocations played in the growth of crystals.
Split into simpler sentences: After the war he moved to the University of Bristol Physics Department to do research in solid state physics, but switched to research on crystal dislocation. His work with Burton and Cabrera was to demonstrate the role dislocations played in the growth of crystals.