Structural, magnetic and magnetocaloric investigation of La0.67Ba0.33Mn1−xNixO3 (x = 0, 0.025 and 0.075) manganite

• Published in: Journal of materials science. Materials in electronics Vol. 29; no. 20; pp. 17187 - 17194
• Main Authors: Kharrat, N., Chihaoui, S., Cheikhrouhou-Koubaa, W., Koubaa, M., Cheikhrouhou, A.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.10.2018; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Composition; Ferromagnetism; Magnetic fields; Magnetic properties; Magnetism; Manganites; Materials Science; Optical and Electronic Materials; Refrigeration; Sol-gel processes; Structural analysis; Transition temperature
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-018-9810-9

In this paper, we report the structural, magnetic and magnetocaloric properties of Ni-doped La 0.67 Ba 0.33 Mn 1−x Ni x O 3 (x = 0, 0.025 and 0.075) manganites. Our compounds were synthesized using the sol–gel method. The structural analysis using Rietveld refinement shows that Ni-doped LaBaMnO 3 system crystallizes in the rhombohedral symmetry with R 3 ¯ c space group. Magnetization measurements versus temperature in a magnetic applied field of 0.05 T reveal that all the compositions exhibit a transition from a ferromagnetic to paramagnetic phase with increasing temperature. A systematic decrease in the transition temperature is clearly observed upon Ni doping and a near room temperature T C (302 K) is achieved with x = 0.075 composition. The maximum magnetic entropy change - Δ S M max in a magnetic field change of 5 T is found to be 2.12, 2.78 and 1.78 J/kg K for x = 0, 0.025 and 0.075, respectively. At this value of magnetic field, large relative cooling power values are obtained in our samples, especially for x = 0.075 (271 J/kg) making it a promising candidate for magnetic refrigeration near room temperature.