Effect of Bi Substitution on Transport and Magnetoresistance Properties of Electron-Doped La0.7−x Bi x Ce0.3MnO3 Ceramics

• DOI: 10.1007/s10948-015-2971-3
• Publication Date: 2015-02-01T23:25:40Z
• Authors: M. A. Ghani; S. N. Supardan; A. K. Yahya
• Keywords: Colossal Magnetoresistance

Colossal magnetoresistance (CMR) ceramics with starting composition of La0.7−x Bi x Ce0.3MnO3 (x = 0–0.15) were synthesized using the conventional solid-state synthesis method to investigate the effect of Bi substitution on their magnetic and electrical transport properties. The undoped sample (x = 0) showed paramagnetic to ferromagnetic (PM-FM) transition at Curie temperature, T c = 248 K and metal to insulator (MI) transition at T MI = 231 K which decreases with Bi content (0 < x < 0.15) indicating weakening of FM phase. At x = 0.15, the susceptibility, χ′ was observed to decrease below 83 K which indicates presence of antiferromagnetic (AFM) clusters in the sample. The decrease in T c and T MI is suggested to be due to the weakening of DE-like interaction involving Mn2+ and Mn3+ as a result of the hybridization between Bi3+ 6 s 2 lone pair with O orbital which increases electron localization. Fitting of the experimental data in the metallic region to scattering models suggested scattering involving electron-electron, electron-magnon, Kondo-like spin-dependant scattering, and electron-phonon interaction. On the other hand, fitting in the insulating region suggests resistivity behavior obeys the adiabatic small polaron hopping (SPH) model.