Magnetotransport properties of c-axis oriented La_(1-x)Sr_xMnO_(3-δ) thin films fabricated by sol-gel spin-coating method

摘要

The anomalously colossal magnetoresistance (CMR) in the La_(1-x)D_xMnO_3 (D = Ba, Sr, Ca, Pb or vacancies) systems has spurred renewed interest n studying these doped perovskites [1-4]. Besides the basic science, the studies have also been motivated by the potential field-sensor and electronic device applications of these materials, especially for lanthanum manganite films. A number of studies have been carried out on the structural and magnetotransport properties of polycrystalline, single crystal, and thin film samples of doped manganites [5-8]. However, most of the investigations show that the ferromagnetic Curie temperature and the metal-semiconductor transition temperature in such materials are strongly dependent on the preparation routine. Magnetic properties in thin films was interpreted in terms of substrate-induced stress [9]. Well-characterized, high-quality lanthanum manganite films of these CMR materials are thus vital for further practical studies.