Study of the Magnetocaloric Effect by Means of Theoretical Models in La0.6Ca0.2Na0.2MnO3 Manganite Compound

Abstract

In this work, an overview of the Weiss molecular mean-field theory, the Bean-Rodbell model, and the Landau theory is presented, providing the theoretical background for simulating the magnetocaloric properties for La0.6Ca0.2Na0.2MnO3 manganite. Results showed that sample exhibits second order ferromagnetic (FM)paramagnetic (PM) magnetic phase transition and relatively higher values of magnetic entropy change (-∆SM). In application point of view, this material can be used in magnetic refrigeration technology. The theoretical values of -∆SM determined using each theory agree well with the experimental ones estimated from Maxwell relations. In other part, a good agreement in the spontaneous magnetization values, Mspont(T), estimated from (-∆SM vs. M 2 ) and (H/M vs. M 2 ) data was found. Also, the values of the critical exponent (β) found from both methods are close and check that the mean field model is adequate to study the MCE in La0.6Ca0.2Na0.2MnO3 sample.

Investigations on Strong-Tuned Magnetocaloric Effect in La0.5Ca0.1Ag0.4MnO3

“…It is preferable to use MC materials that have a magnetic transition type of the second degree with a suitable Curie temperature (θ C ) as appropriate for use in a wide temperature range, including room temperature (Choura-Maatar et al, 2020;Henchiri et al, 2020;Laajimi et al, 2020). The current efforts are directed towards the use of manganite as an effective substance in MRs due to its great chemical stability during frequent use, lack of eddy current, ease of preparation, high electrical resistance, and the possibility of improving their properties through doping and changing the oxygen content (Alzahrani et al, 2020;Choura-Maatar et al, 2020;Henchiri et al, 2020;Laajimi et al, 2020). Felhi et al prepared La 0.5 Ca 0.1 Ag 0.4 MnO 3 (LCAMO) via the ceramic method and reported an increase in H ext and an increase in broad ferromagnetic (FM) phase transition of LCAMO covering room temperature under high H ext (Jeddi et al, 2020).…”

Theoretical analysis of magnetic properties and the magnetocaloric effect using the Blume-Capel model

“…Research on the properties of MCE and its applications has been growing both in the theoretical research [5][6][7][8][9][10][11][12] and in the experimental research [13][14][15][16][17][18][19]. From a theoretical point of view, statistical mechanics models are effective tools in the study of the thermodynamic and magnetic properties of materials.…”

Strong Role of Calcination Temperature for Improving Magnetocaloric Effect in Nd0.5Sr0.5MnO3 Prepared via Combustion Technique

“…With rapid steps, increased refrigeration efficiency, reduction in weight, greater mechanical stability, lower environmental impact, greater efficiency, lower noise levels and high cost-effectiveness, magnetocaloric refrigerator (MR) has developed into a strong alternative to gas refrigeration by magnetocaloric effect (MCE) [1][2][3][4][5][6]. In space applications, medical appliances, aerospace applications and food cooling, MR is a fundamental requirement [7][8][9][10][11][12][13][14].…”