The Preparation And Physical Properties Of La_0.67Ca_0.33Mn_1-xFe_xO₃ Films

Perovskite-type manganese oxide has CMR etc. physical properties andits great application potential ,so it has been studied extensively.In this paper, solidstate reaction method were preparaed for La_0.67Ca_0.33Mn_1-xFe_xO₃ solid targets.XRDshowed that the targets are homogenous phase and typical perovskite-Typestructure and show sigle phase , space group Pnma.The calculation of rA is lessthan the average radius of the distortion threshold, so targets are orthorhombicstructure. Film samples are depodited on the LAO (100), MgO (100) by radiofrequency magnetron sputtering instrument, the work of the main parameters : thesubstrate temperature was 780℃, the oxygen argon ratio of 4:1, Sputtering powerof 200W.Then they are annealed in900℃under O₂ to eliminate the inner stress.La_0.67Ca_0.33Mn_0.9Fe_0.1O₃/LAO thin films may occur in antiferromagneticphase, thus affecting the film sample magnetization and resistivity properties.For the film La_0.67Ca_0.33MnO₃/LAO, La_0.67Ca_0.33MnO₃/MgO, theelectrical transport properties refect Metal-Semiconductor transaction (mark thetemperature as T_MS) in zero and five field. In the five Tesla, the double-exchangeinteraction is enhanced ,leading to ascension of resistance . The incorporation of acertain amount of Fe, regardless of LAO substrate or MgO substrates comparedwith the undoped samples, the resistivity the film La_0.67Ca_0.33Mn_0.9Fe_0.1 haveincreased significantly, meanwhile T_MS has dropped significantly.Finally, we have studied infrared absorption spectra of the films andobserved the vibration peak of the corresponding external model (EM), bendingmode vibration peak (BM) and the stretching mode vibration peak (SM) . WeObtained the carrier number of samples by K-K transformation .It refect there is arealationship between carrieris and resitivity...