Thickness-dependent magnetotransport in ultrathin manganite films

To understand the near-interface magnetism in manganites, ultrathin films o f La0.67Sr0.33MnO3 were grown epitaxially on single-crystal (001) LaAlO3 an d (110) NdGaO3 substrates. The temperature and magnetic field-dependent fil m resistance is used to probe the film's structural and magnetic properties . A surface and/or interface related dead layer is inferred from the thickn ess-dependent resistance and magnetoresistance. The total thickness of the dead layer is estimated to be similar to 30 Angstrom for films on NdGaO3 an d similar to 50 Angstrom for films on LaAlO3. (C) 1999 American Institute o f Physics. [S0003-6951(99)02420-1].