Abstract
A detailed study of the structural, magnetic, magnetocaloric and electrical effect properties in polycrystalline manganite La
0.5
Sm
0.1
Sr
0.4
Mn
0.975
In
0.025
O
3
is presented. The X-ray diffraction pattern is consistent with a rhombohedral structure with
R
3̄
c
space group. Experimental results revealed that our compound prepared
via
a sol–gel method exhibits a continuous (second-order) ferromagnetic (FM) to paramagnetic (PM) phase transition around the Curie temperature (
T
C
= 300 K). In addition, the magnetic entropy change was found to reach 5.25 J kg
−1
K
−1
under an applied magnetic field of 5 T, corresponding to a relative cooling power (RCP) of 236 J kg
−1
. We have fitted the experimental data of resistivity using a typical numerical method (Gauss function). The simulation values such as maximum resistivity (
ρ
max
) and metal–semiconductor transition temperature (
T
M–Sc
), calculated from this function, showed a perfect agreement with the experimental data. The shifts of these parameters as a function of magnetic field for our sample have been interpreted. The obtained values of
β
and
γ
, determined by analyzing the Arrott plots, are found to be
T
C
= 298.66 ± 0.64 K,
β
= 0.325 ± 0.001 and
γ
= 1.25 ± 0.01. The critical isotherm
M
(
T
C
,
μ
0
H
) gives
δ
= 4.81 ± 0.01. These critical exponent values are found to be consistent and comparable to those predicted by the three-dimensional Ising model with short-range interaction. Thus, the Widom scaling law
is fulfilled.
Rietveld refinement for the sample LSSMIO. Experimental data (the point symbols), calculated data (the solid lines), difference between them is shown at the bottom of the diagram and Bragg positions are marked by vertical bars.