Influence of Dy addition on the magnetocaloric effect of La0.67Ca0.33Mn0.9V0.1O3 ceramics

• Published in: Journal of magnetism and magnetic materials Vol. 324; no. 1; pp. 37 - 43
• Main Authors: Nisha, P., Savitha Pillai, S., Suresh, K.G., Raama Varma, Manoj
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.01.2012; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Domain effects, magnetization curves, and hysteresis; Exact sciences and technology; Inorganic compounds; Magnetic phase boundaries (including magnetic transitions, metamagnetism, etc.); Magnetic properties and materials; Magnetically ordered materials: other intrinsic properties; Magnetization curves, magnetization reversal, hysteresis, barkhausen and related effects; Magnetocaloric effect; Magnetocaloric effect, magnetic cooling; Physics; Reitveld refinement; Relative cooling power; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; X-ray diffraction; X-ray diffraction; Reitveld refinement; Relative cooling power; Magnetocaloric effect; Temperature dependence; Rietveld method; Transition temperature; Space groups; Cooling; Magnetization; Maximum entropy methods; Property composition relationship; Entropy; XRD; Lattice parameters; Magnetic transitions; Heat treatments; Magnetocaloric effects; Orthorhombic lattices; Dysprosium additions; Thermodynamic properties; Power law; Crystal structure
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2011.07.032

The influence of partial substitution of La by Dy on the magnetocaloric response of (La1−xDyx)0.67Ca0.33Mn0.9V0.1O3, where x=0.03, 0.15 and 0.25 is studied. Rietveld refinement of X-ray diffraction pattern using GSAS method shows that the compounds adopt the orthorhombic structure with Pnma space group. The systematic change in lattice parameters and magnetic phase transition indicates the substitution effect of Dy. From the magnetization isotherms at different temperatures, magnetic entropy change close to their respective transition temperatures (TC) has been evaluated. The maximum value of entropy change near TC is found to be about 4.8J/kgK at 187.5K for LCMVDy0.03, 2.45J/kgK at 107.5K for LCMVDy0.15 and 2.15J/kgK at 92.5K for LCMVDy0.25 at 4T. Dy addition produces a reduction in TC and in magnitude of the magnetic entropy change. Even though the entropy change decreases with increasing Dy substitution the refrigerant temperature range, ΔT, is found to be 10K for LCMVDy0.03, 31K for LCMVDy0.15 and 35K for LCMVDy0.25 compounds [90%] at 4T. The field dependence of the magnetic entropy change is also analyzed showing the power law dependence, ΔSM∞Hn where n=0.75(2) for LCMVDy0.03, n=0.80(4) for LCMVDy0.15 and n=0.92(8) for LCMVDy0.25 compounds at their respective transition temperatures. The relative cooling power and its field dependance are also analyzed. ► Studied magnetocaloric response of Dy substituted solid state synthesized LCMVO. ► Studied the field dependence of the magnetic entropy change (ΔSM∞Hn). ► Studied the field dependence of Relative cooling power (RCP∞H1+1/δ). ► Considerably large magnetocaloric effect and moderate relative cooling power.