Microstructure and transport properties of sol-gel fabricated La0.7Sr0.3MnO3 nanocrystalline films on Si(100) substrates

Nanocrystalline La0.7Sr0.3MnO3 films are fabricated on Si(100) substrates by sol-gel method. The annealing temperature dependence of grain size, film morphology and transport properties is investigated. The films with less texture exhibit a large magnetoresistance that is both low-field sensitive and relatively temperature independent over a wide temperature range. In addition, when the temperature is far below T-c, the resistivity increases rapidly with decreasing temperature. This effect has been attributed to the spin-polarized tunneling between grain boundaries. (C) 2000 Elsevier Science S.A. All rights reserved.