A high-resolution magneto-optical imaging technique was used to reveal the formation of twins during a martensitic phase transition at about 105K in La2/3Ca1/3MnO3 films which had been grown onto SrTiO3 substrates. A magnetic contrast arose due to the magneto-elastic tilts of the Mn magnetic moments in the twins.

Observation of the Structural Phase Transition in Manganite Films by Magneto-Optical Imaging. V.K.Vlasko-Vlasov, Y.Lin, U.Welp, G.W.Crabtree, D.J.Miller, V.I.Nikitenko: Journal of Applied Physics, 2000, 87[9], 5828-30