Abstract
The single-phase intermetallic compounds GdFe12−xCrx (x = 2, 2.5 and 3), elaborated by arc-melting method and annealed at 1073 K, crystallize in the ThMn12-type structure with the I4/mmm space group. The structural, magnetic and magnetocaloric properties of these intermetallic compounds were studied extensively by means of X-ray powder diffraction (XRD), Mössbauer spectrometry and magnetic measurements. The Rietveld analysis of X-ray diffraction patterns reveals that the lattice parameters of GdFe12−xCrx (x = 2, 2.5 and 3) compounds increase linearly with increasing Cr content up to x = 3, and proves that Cr atom prefers 8i sites in the ThMn12 structure and that Fe occupies 8i, 8f and 8j. The Mössbauer spectra study based on the Wigner-Seitz cell volumes correlation with the isomer shift parameter of each specific site 8i, 8f and 8j, confirms the preferred inequivalent crystallographic site of Cr atoms. Ab initio calculations of GdFe12−xCrx were performed using the density functional theory (DFT) based on the full potential linearized augmented plane wave (FLAPW). The calculated data are in good agreement with the results of the magnetic measurements as well as with the Mössbauer spectrometry. The variation of magnetization (M) vs. temperature (T) reveals that all compounds exhibit a second-order ferromagnetic to paramagnetic phase transition in the vicinity of the Curie temperature (TC). The substitution of Fe by Cr yields enhancement of the magnetic ordering transition temperature. The maximum magnetic entropy change (ΔSM) was estimated from isothermal magnetization curves and it increases from 1.82 J/kg.K for x = 2, to 2.95 J/kg.K for x = 3, under a field change of 1.5 T. The relative cooling power (RCP) is in the range of 12.5 J/kg for x = 2 and 30.4 J/kg for x = 3. Our results suggest that such substituted compounds could be considered as a potential candidate for magnetic refrigeration technology.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
