MAGNETO-TRANSPORT IN Mo-DOPED LaMnO3 AND YIG

Abstract

The aim was to investigate the impact of substituting molybdenum ions (Mo) at the manganese sites (Mn) of lanthanum manganites (LaMnO3) in terms of its structure, dc magnetotransport, ac magnetoresistance and dynamic properties through the analysis of temperature and field-dependence of magnetization, X-ray diffraction, broadband FMR and electrical resistivity (ρ) and thermopower (S). Samples of LaMn1-xMoxO3 (0 ≤ x ≤ 0.1) were prepared via the solid-state conventional heating (CH) and Microwave (MW) routes. Substituting Mo ions (x ≤ 0.06) at the Mn-site induces a mixed valence of Mn2+ and Mn3+, which enhances the Zener's double exchange (DE) interaction and leading to significant change to the curie temperature (TC), insulating-metallic transition temperature (TMI), saturation magnetization (Msat), temperature where the thermopower peaks (TS) and ρ. Additionally, temperature-dependence magnetic resonance data indicated the presence of ferromagnetic FM clusters at the paramagnetic (PM) regime by the exhibition of multiline spectra near the TC. For x > 0.06, the valence of Mo ions changes from 6+ to 5+ and there is an existence of Mn4+ on top of the already-present Mn2+ and Mn3+ ions.