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<p>Polycrystalline perovskite La<sub>0.68</sub>Sm<sub>0.1</sub>K<sub>0.22</sub>Mn<sub>0.99</sub>O<sub>3−δ</sub> has been elaborated following a conventional solid-state method. X-ray powder diffraction and Rietveld refinement prove that the compound crystallizes in the rhombohedral (<i>R-3c</i>) space group, with lattice paremeters <i>a</i> = 5.51129 Å, <i>c</i> = 13.42700 Å at RT. The rhombohedral phase is further supported by Raman spectroscopy analysis. The temperature dependence of DC-magnetization has revealed that the sample exhibits a paramagnetic to ferromagnetic phase transition and magnetic disorder, with a Curie temperature T<sub>C</sub> = 214&#xa0;K, corresponding to a double-exchange interaction. It is also evident the presense of a Griffiths-like phase above T<sub>C</sub>. Covalent and ionic interactions stabilize the structure as evidenced by the calculated 2D-electron density and Hirshfield surface analysis. The magnetocaloric properties, entropy (<InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(\:{\varDelta\:\text{S}}_{\text{M}}\)</EquationSource> </InlineEquation>), relative cooling power (RCP), and heat capacity (ΔC<sub>P</sub>) have been investigated theoretically by using experimental magnetization data. The maximum entropy change, <InlineEquation ID="IEq2"> <EquationSource Format="TEX">\(\:|-{\varDelta\:\text{S}}_{\text{M}}^{\text{m}\text{a}\text{x}}|\)</EquationSource> </InlineEquation>, reaches the highest value of 0.088&#xa0;J kg<sup>− 1</sup> K<sup>− 1</sup> under an applied magnetic field of 0.1 T, which may be an interesting value for magnetic refrigeration.</p> Graphical Abstract <p></p>

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Structural, magnetic and theoretical investigations on the magnetocaloric properties inLa0.68Sm0.1K0.22Mn0.99O3-δ compound

  • 期刊论文

  • 发表日期：

    2026年7月13日

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  • R. Selmi,
  • W. Cherif,
  • L. Fernández Barquín,
  • María de la Fuente,
  • L. Ktari

摘要

Polycrystalline perovskite La0.68Sm0.1K0.22Mn0.99O3−δ has been elaborated following a conventional solid-state method. X-ray powder diffraction and Rietveld refinement prove that the compound crystallizes in the rhombohedral (R-3c) space group, with lattice paremeters a = 5.51129 Å, c = 13.42700 Å at RT. The rhombohedral phase is further supported by Raman spectroscopy analysis. The temperature dependence of DC-magnetization has revealed that the sample exhibits a paramagnetic to ferromagnetic phase transition and magnetic disorder, with a Curie temperature TC = 214 K, corresponding to a double-exchange interaction. It is also evident the presense of a Griffiths-like phase above TC. Covalent and ionic interactions stabilize the structure as evidenced by the calculated 2D-electron density and Hirshfield surface analysis. The magnetocaloric properties, entropy ( \(\:{\varDelta\:\text{S}}_{\text{M}}\) ), relative cooling power (RCP), and heat capacity (ΔCP) have been investigated theoretically by using experimental magnetization data. The maximum entropy change, \(\:|-{\varDelta\:\text{S}}_{\text{M}}^{\text{m}\text{a}\text{x}}|\) , reaches the highest value of 0.088 J kg− 1 K− 1 under an applied magnetic field of 0.1 T, which may be an interesting value for magnetic refrigeration.

Graphical Abstract