Magnetic properties of doped LaMnO3 ceramics obtained by a polymerizable complex method

Abstract

Substituted lanthanum manganites with the general formula A(1-x) B (x) MnO3 (A = La, B = Ca, SraEuro broken vertical bar) have attracted a lot of attention due to their exceptional electric and magnetic properties. In this work, pure and Ca2+, Sr2+-doped LaMnO3 (LMO) with the concentrations of dopants 30% Ca2+ (LCMO), 30% Sr2+ (LSMO) and 15% Ca2+ + 15% Sr2+ (LCSMO) (in mol. %) were synthesized by polymerizable complex method. Bulk samples were prepared by sintering at 1300 A degrees C for 4 h in oxygen atmosphere. It was found that sintering in oxygen atmosphere enables preparation of single phase ceramics with rhombohedral crystal structure. Chemically prepared fine, submicronic precursor powders provided uniform microstructure and grain size distribution in final ceramics. As a result, pure and doped LMO ceramics with excellent microstructural and magnetic properties were obtained. Depending on the composition, magnetic measurements showed high saturation magnetizations (up to 93 emu/g), with values of the Curie temperature in the range 180-390 K and magnetoresistance up to 67%.