Magnetic domain landscape in a TbGdFeCo film. The 180 nm thick film was deposited on a 100 nm thick Cr underlayer/glass at 200 C and 4 mTorr argon gas pressure using DC magnetron sputtering. Similar multi-layer films have been used for the Bose-Einstein condensation of rubidium atoms on an atom chip.

Image courtesy of Dr James Wang, Prof Andrei Sidorov and Prof Peter Hannaford, ARC Centre of Excellence for Quantum-Atom Optics, Swinburne University of Technology, Melbourne, Australia.