International Journal of Physics | Vol. 3, No. 7, July 2012 | pp. 51–58
DOI: 10.46882/2012/IJP/000027
Research Article
Title: Magnetic Phase Transitions and Magnetocaloric Effects in Rare-Earth Intermetallic Compounds
Names of Authors: O. B. Ivanov¹, G. W. McKenzie²
Authors’ Affiliations: ¹L.D. Landau Institute for Theoretical Physics, Russian Academy of Sciences, Chernogolovka 142432, Russia; ²School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom
Abstract: Rare-earth intermetallic compounds draw substantial research attention due to their potential application in energy-efficient magnetic refrigeration technology. This investigation models the magnetic phase transitions and characterizes the magnetocaloric effect in Gd5(Si²Ge²-xSnx) compounds where x varies systematically from 0.0 to 0.5. We utilized a comprehensive combination of mean-field theory calculations, Monte Carlo simulations, and direct magnetizations measurements. The empirical data indicate a first-order magneto-structural phase transition shifting toward lower temperatures as the tin (Sn) content increases. For the specific composition where x = 0.1, we recorded a substantial magnetic entropy change value of -14.2 J/(kg*K) under an applied external magnetic field swing of 0 to 5 T. The corresponding adiabatic temperature adjustment was measured directly at ΔT = 5.4 K near the Curie temperature benchmark of 245 K. The calculations reveal that substituting silicon and germanium with tin atoms expands the host crystal lattice volume by 1.2%. This structural expansion modifies the indirect RKKY exchange interaction coupling constants significantly. Consequently, this material tuning effectively optimizes the operating window of the magnetocaloric effect for commercial climate control applications.
Keywords: Magnetocaloric effect; magnetic refrigeration; intermetallic compounds; phase transitions; Monte Carlo simulation; Curie temperature
Manuscript Timeline: Received: April 22, 2012; Revised: June 1, 2012; Accepted: June 15, 2012; Published: July 12, 2012
Citation: Ivanov, O. B., & McKenzie, G. W. (2012). Magnetic Phase Transitions and Magnetocaloric Effects in Rare-Earth Intermetallic Compounds. International Journal of Physics, 3(7), 51–58.
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