I have recently joined university of Rostock for my PhD degree. It is mainly focused on the Spectroscopy techniques specially IR and UV-vis together with electroanalytical techniques.
I feel its quite interdisciplinary I you can get to learn about different domains as well. Regarding the city I would say its quite peaceful and it amazing in summers specially. You can have a good walk beside the harbor. The Baltic see is amazing and you can spend good time on Warnemunde beach as well.