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Title: Tunable magnetic and magnetocaloric properties of La{sub 0.6}Sr{sub 0.4}MnO{sub 3} nanoparticles

Journal Article · · Journal of Applied Physics
DOI:https://doi.org/10.1063/1.4846758· OSTI ID:22266153
 [1];  [2]; ;  [3]
  1. Department of Physics, Isfahan University of Technology, Isfahan 84156-8311 (Iran, Islamic Republic of)
  2. Department of Physics, Shahrood University, Shahrood (Iran, Islamic Republic of)
  3. Department of Physics, Brock University, St.Catharines, Ontario L2S 3A1 (Canada)

Nanoparticles of La{sub 0.6}Sr{sub 0.4}MnO{sub 3} with different particle sizes are synthesized by the nitrate-complex auto-ignition method. The structural and magnetic properties of the samples are investigated by X-Ray diffraction (XRD), Fourier transform infra-red (FT-IR) spectroscopy, transmission electron microscopy (TEM), and DC magnetization measurements. The XRD study coupled with the Rietveld refinement shows that all samples crystallize in a rhombohedral structure with the space group of R-3 C. The FT-IR spectroscopy and TEM images indicate formation of the perovskite structure with the average sizes of 20, 40, and 100 nm for the samples sintered at 700, 800, and 1100 °C, respectively. The DC magnetization measurements confirm tuning of the magnetic properties due to the particle size effects, e.g., reduction in the ferromagnetic moment and increase in the surface spin disorder by decreasing the particle size. The magnetocaloric effect (MCE) study based on isothermal magnetization vs. filed measurements in all samples reveals a relatively large MCE around the Curie temperature of the samples. The peak around the Curie temperature gradually broadens with reduction of the particle size. The data obtained show that although variations in the magnetic entropy and adiabatic temperature decrease by lowering the particle size, variation in the relative cooling power values are the same for all samples. These results make this material a proper candidate in the magnetic refrigerator application above room temperature at moderate fields.

OSTI ID:
22266153
Journal Information:
Journal of Applied Physics, Vol. 114, Issue 22; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
Country of Publication:
United States
Language:
English