Electrical resistivity and magnetoresistive behaviour of bismuth-substituted lanthanum manganites La0.4Bi0.1Ca0.5–𝑥Sr𝑥MnO3 (𝑥 = 0.1 and 0.2) were systematically studied by varying the temperature from 2 to 300 K and the magnetic field up to 12 T. The samples were found to crystallize in rhombohedral structure and their morphology shows near-spherical nanosize crystallites. Charge ordering was observed in both the samples under zero field conditions and corresponding transition temperature 𝑇CO was found to decrease with the increase of 𝑥. Resistivity measurements with magnetic field also showed suppression of magnetoresistivity (MR) with the increase of 𝑥 and the maximum MR was found to be 98 and 93% for 𝑥 = 0.1 and 0.2, respectively, at 10 T. In the high-temperature domain, the electronic transport was observed to be dominated by the variable range hopping mechanism for both the samples, whereas in the low-temperature domain the electrical conduction of 𝑥 = 0.1 sample was observed to be contributed by various other electron scattering mechanisms.
Volume 43, 2020
Continuous Article Publishing mode
Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020
Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
Physical Sciences 2020
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