Prediction of magnetoresistance using a magnetic field and correlation between the magnetic and electrical properties of La0.7Bi0.05Sr0.15Ca0.1Mn1−xInxO3 (0 ≤ x ≤ 0.3) manganite

Abstract

In this paper, we have systematically investigated the effect of In doping on the magnetic and magnetocaloric effect (MCE) in La_0.7Bi_0.05Sr_0.15Ca_0.1Mn_1−xIn_xO₃ (0 ≤ x ≤ 0.3) manganite. All of the samples exhibit a second-order magnetic phase transition from the ferromagnetic to the paramagnetic state at the Curie temperature (T_C). From the measurements of isothermal magnetization around (T_C), we have determined the magnetic entropy change (ΔS_M). It has been found that there was a large (ΔS_M), i.e. a large (MCE), in all samples. Among them, a maximum (ΔS_M) and the highest relative cooling power (RCP) under the magnetic field of 5 T are found to be 6.14 J kg⁻¹ K⁻¹ and 281 J kg⁻¹, respectively for x = 0. This investigation suggests that our samples would be suitable candidates for magnetic refrigeration technology. The relationship between resistivity and magnetization was performed as ρ = ρ₀ exp(−M/α). The (MCE) was investigated based on the resistivity measurements. The obtained results were discussed. A typical numerical method (Gauss function) was used for fitting the experimental data of resistivity. The simulation values such as metal–semiconductor transition temperature (T_M–Sc) and maximum resistivity (ρ_max), calculated from this function, showed promising agreement with the experimental data. The shifts of these values as a function of magnetic field for all samples have been interpreted.