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Title: Magnetic and magnetocaloric properties of La{sub 0.85}(Na{sub 1−x}K{sub x}){sub 0.15}MnO{sub 3} ceramics produced by reactive spark plasma sintering

La{sub 0.85}(Na{sub 1−x}K{sub x}){sub 0.15}MnO{sub 3} (0 ≤ x ≤ 1) ceramics were synthesized from the raw La(OH){sub 3}, NaOH, KOH, and MnO{sub 2} powders using Reactive Spark Plasma Sintering. All the compounds were obtained as pure, dense, and ultrafine grained pellets. The Rietveld refinement of the X-Ray powder diffraction shows that all our synthesized samples are single phase and crystallize in the distorted rhombohedral system with R-3c space group. The thermal variation of their magnetization under a magnetic applied field of 50 mT shows a paramagnetic to ferromagnetic transition at a Curie temperature very close to room temperature. The magnetic entropy change, deduced from magnetization measurements versus magnetic applied field up to 5 T at several temperatures exhibits a maximum |ΔS{sub M}|{sub max} which slightly increases with increasing K content. The relative cooling power values, inferred from the |ΔS{sub M}| vs T peak broadening, vary slightly with the potassium content, reaching, values between 316 and 289 Jkg{sup −1}, in an applied magnetic field of 5 T, when x increases from 0 to 1. Technically, these large values make the prepared materials very promising for domestic magnetic refrigeration.
Authors:
 [1] ;  [2] ; ;  [1] ;  [3] ; ;  [4]
  1. ITODYS, Université Paris Diderot, PRES Sorbonne Paris Cité, CNRS-UMR 7086, 75205 Paris (France)
  2. (Tunisia)
  3. ICMPE, Université Paris-Est, CNRS UMR-7182, 94320 Thiais (France)
  4. LPM, Faculté des Sciences de Sfax, Université de Sfax, 3000 Sfax (Tunisia)
Publication Date:
OSTI Identifier:
22273837
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 17; Conference: 55. annual conference on magnetism and magnetic materials, Atlanta, GA (United States), 14-18 Nov 2010; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CERAMICS; CURIE POINT; LANTHANUM HYDROXIDES; MAGNETIC FIELDS; MAGNETIZATION; MANGANESE OXIDES; PARAMAGNETISM; POTASSIUM; POTASSIUM HYDROXIDES; POWDERS; SINTERING; SODIUM HYDROXIDES; TEMPERATURE RANGE 0273-0400 K; TRIGONAL LATTICES; X-RAY DIFFRACTION