Structure and Dielectric Properties of Mg, Cr-doped LaSrFeO_3 Films

摘要

Mg-doped LaFeO_3 thin film and Mg, Cr-doped La_(0.5)Sr_(0.5)FeO_3 thin films were prepared by the sol-gel method. The change rules of structure and dielectric properties of the films were studied by XRD, SEM, and Agilent. The dielectric properties of La_(0.5)Sr_(0.5)FeO_3 and LaFeO_3 films were improved by the substitute with Mg and Cr. The doping amount of Mg and Cr for the optimal dielectric properties of La_(0.5)Sr_(0.5)FeO_3 films is 45mol%, 25mol%, respectively, and for LaFeO_3, the doping amount of Mg is 8mol%. The observed pure perovskite phase of the doped films suggested the dissolution of Mn, Co, and Ni in La_(0.5)Sr_(0.5)FeO_3 crystal lattice. Mg and Cr were integrate in the lattice of LaFeO_3 and La_(0.5)Sr_(0.5)FeO_3, and mineral is single perovskite phase. The surface of the film is smooth, without cracks, surface grain size distribution and had uniform grain size.