Room-temperature and low-field magnetoresistance of La-Sr-Mn-O thin films

摘要

Thin films of La/sub 0.71/Sr/sub 0.29/Mn/sub 1.01/O/sub 3-/spl delta// have been sputtered onto polycrystalline YSZ, [110] sapphire, YSZ buffered Si and [100] SrTiO/sub 3/ substrates. Microstructure and magnetotransport properties of these films are investigated. Except for the epitaxial film on [100] SrTiO/sub 3/ substrate, granular structures with 20-100 nm grains in size are observed. In the granular films, resistance changes about 0.5% within a field of 100 Oe are observed at room-temperature. The resistivity and the hysteretic behavior of the magnetoresistance are varied with substrate material. The low-field magnetoresistance is related to the microstructure and the magnetization process.