Monte Carlo Study of the Magnetic and Magnetocaloric Properties of La₁-_xCa_xMnO₃ (x = 0.33 and 0.5)

Abstract

In our work the temperature dependencies of magnetization, entropy changes, and the Curie temperature (TC) of La1-xCaxMnO3 (x = 0.33 and 0.5) were investigated using Monte Carlo method and Heisenberg model. In our simulation, magnetic Mn3+ and Mn4+ ions are described by classical Heisenberg spins, while oxygen, lanthanum and calcium ions are considered as non-magnetic. The Mn magnetic ions are distributed on a simple cubic lattice according to the perovskite structure of the manganite. The theoretical Curie temperatures and magnetocaloric values are in a good agreement well with experimental data.

Magnetic properties of (La0.56Ce0.14)Sr0.30MnO3 perovskite

“…Putting T c = 357 K in Eq. (7), we obtain J ef f ≃ 21.24 K. Note that in magnetic materials with Curie temperatures at room or higher temperatures the effective exchange interaction is of the order of several dozens of Kelvin [8,48,49]. of J 1 is ≃ 21.24 K which is lower.…”

Magnetic Properties of (La0.56Ce0.14)Sr0.30MnO3 Perovskite

“…Putting T c = 357 K in Eq. ( 7), we obtain J ef f ≃ 21.24 K. Note that in magnetic materials with Curie temperatures at room or higher temperatures the effective exchange interaction is of the order of several dozens of Kelvin [8,48,49]. In the works of Restrepo-Parra et al and of Pavlukhina et al, by fitting experimental values of the transition temperatures for different regions of doping concentration x, the authors have deduced the values of different kinds of exchange interactions, in a similar manner to ours.…”

Influence of Fe doped on the magnetocaloric behavior of La$_{{2}/{3}}$ Ca$_{{1}/{3}}$ Mn1−xFexO3compounds: a Monte Carlo simulation

“…Furthermore, according to Simopoulos et al, at low temper atures, iron mainly exhibits an ionization state of Fe 3+ , with S = 5 2 [30]. The ferromagnetic character of LCMO is mainly due to double exchange effect between Mn 3+ and Mn 4+ ions [31].…”

“…In the last two decades, several works have been done on the electrical, magnetic thermal and magnetocaloric effect in rareearth doped manganites of the type RE 1−x Ca x MnO 3, where RE is a rareearth element [5][6][7][8]. One of these com pounds are the manganites as La 1−x Ca x MnO 3 (LCMO), which not only exhibit firstorder magnetic phase transitions but also a ferromagnetic metallic phase in a robust density range, i.e.…”