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

Mahmoud A Hamad,Hatem R Alamri

doi:10.3389/fmats.2022.832703

Abstract

The magnetocaloric effect (MCE) of La0.5Ca0.1Ag0.4MnO3 (LCAMO) is simulated using a phenomenological model (PM). The LCAMO MCE parameters are calculated as the results of simulations for magnetization vs. temperature at different values of external magnetic field (Hext). The temperature range of MCE in LCAMO grew as the variation in Hext increased, eventually covering the room temperature at high Hext values. The MCE of LCAMO is tunable with the variation of Hext, proving that LCAMO is practically more helpful as a magnetocaloric (MC) material for the development of magnetic refrigerators in an extensive temperature range, including room temperature and lower and higher ones. The MCE parameters of LCAMO are practically greater than those of some MC samples in earlier works.

Highlights

This work demonstrates the good coincidence between the experimental data and the continuous curves given by phenomenological model (PM), indicating that this model allows us to predict the magnetocaloric effect (MCE) for LCAMO under different magnetic fields
Though the maximum ΔSM is 2.75 J/kg K upon 5T applied field variation, which is about 57% of the corresponding value of the compound that belongs to the same system as La0.5Ca0.2Ag0.3MnO3 (ΔSMax = 4.8 J/kg K upon 5 T), the value of relative cooling power (RCP) (273.5 J/kg upon 5 T) is larger, and the ΔSM distribution of LCAMO is much more broad than that of La0.5Ca0.2Ag0.3MnO3 (RCP = 168 J/kg δTFWHM = 35 upon 5 T), covering a wider range of temperature (Felhi et al, 2019)
Based on thermodynamic calculation via PM, the MCE of LCAMO is simulated under different values of variation in Hext

Summary

INTRODUCTION

The need to solve the problem of emission of hazard gases, which come out of conventional vapor refrigerators, results in increased interest in functioning magnetic refrigerator (MR), the idea of which depends on functioning magnetocaloric effect (MCE) (Dhahri et al, 2014; ElSayed and Hamad, 2019a; El-Sayed and Hamad, 2019b; Ahmed et al, 2021a, Ahmed et al, 2021b; Hamad et al, 2021; Jebari et al, 2021), because the MR provides high efficiency for cooling without any negative impact on the environment and has low energy consumption, availability of mechanical stability, and fewer noise events during cooling operation (Dhahri et al, 2015; Hamad, 2015a; ErchidiElyacoubi et al, 2018a, ErchidiElyacoubi et al, 2018b; Hamad et al, 2020; Sharma et al, 2020; Belhamra et al, 2021). It is preferable to use MC materials that have a magnetic transition type of the second degree with a suitable Curie temperature (θC) 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). These results motivate us to investigate the MCE of LCAMO, expecting that the MCE of LCAMO covers a large range of temperatures, especially cryogenic temperature and room temperature. The MCE of LCAMO is studied using a phenomenological model (PM) to simulate the isofield magnetization vs temperature curves, concluding with simulated ΔSM, heat capacity change (Δ CP,H), and relative cooling power (RCP). A magnetic cooling efficiency of LCAMO is expected by considering the magnitude of |ΔSMax(T, Hmax)| and δTFWHM (Hamad, 2012). The Δ CP,H of LCAMO can be given as follows (Hamad, 2012):

RESULTS AND DISCUSSION

CONCLUSION

DATA AVAILABILITY STATEMENT