Ferromagnetism of La0. 67Sr0. 33MnO3 is extremely sensitive to external perturbations like substrate-induced strain, charge injection and chemical interactions with neighbour layers. In this paper we discuss the perturbation induced by the presence of a metallic overlayer, typically deposited for electric contacts, in the prototypical case of the Au/La0. 67Sr0. 33MnO3 interface. In particular we found a sizable decrease of the Curie temperature in thin films of La0. 67Sr0. 33MnO3 after gold capping: 65K for 5nm thickness of the manganite. Apart from chemical reactions at the interface, charge injection–depletion induced by the difference in the work function between Au and La0. 67Sr0. 33MnO3 could partially explain this phenomenon.
25 Nov 2007
Volume: 144 Issue: 1 Pages: 93-96
Materials Science and Engineering: B