Scholarlink

<p>This study investigates the structural, magnetic, and magnetocaloric properties of GdMnO<sub>3</sub>, GdMn<sub>0.5</sub>Fe<sub>0.5</sub>O<sub>3</sub>, and GdMn<sub>0.5</sub>Fe<sub>0.25</sub>Al<sub>0.25</sub>O<sub>3</sub> synthesized via the sol–gel autocombustion method. All compounds crystallize in an orthorhombic structure with&#xa0;<i>Pbnm</i>&#xa0;symmetry. X-ray diffraction confirms that GdMnO<sub>3&#xa0;</sub>exhibits an O′-type structure, whereas Fe<sup>3+</sup>-doped and Fe<sup>3+</sup>/Al<sup>3+</sup>-codoped samples adopt an O-type structure. Magnetization measurements reveal that Fe substitution markedly increases the Néel temperature of the Mn/Fe sublattice from ~ 40&#xa0;K in GdMnO<sub>3</sub>&#xa0;to 293&#xa0;K in GdMn<sub>0.5</sub>Fe<sub>0.5</sub>O<sub>3</sub>, and 232&#xa0;K in GdMn<sub>0.5</sub>Fe<sub>0.25</sub>Al<sub>0.25</sub>O<sub>3,</sub>&#xa0;indicating enhanced superexchange interactions. The maximum magnetic entropy change (− Δ<i>Sₘ</i>) occurs near 7.5&#xa0;K, reaching ~ 19, ~ 18, and ~ 14 Jkg<sup>−1</sup>&#xa0;K<sup>−1</sup>&#xa0;under 5&#xa0;T, respectively, primarily due to field-induced ordering of the Gd<sup>3+</sup>&#xa0;sublattice.&#xa0;Conversely, the Mn/Fe sublattice transition near room temperature produces only a modest entropy change. Despite a reduction with co-doping, the magnetocaloric response remains notable among manganites, particularly in the cryogenic temperature range.</p> Graphical abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Dopant-induced structural, magnetic, and magnetocaloric changes in Fe and Al-doped GdMnO3 compound

  • 期刊论文

  • 发表日期：

    2026年7月20日

查看全文
  • Jolaikha Sultana,
  • Santosh Karki Chhetri,
  • Jin Hu,
  • Sanjay R. Mishra

摘要

This study investigates the structural, magnetic, and magnetocaloric properties of GdMnO3, GdMn0.5Fe0.5O3, and GdMn0.5Fe0.25Al0.25O3 synthesized via the sol–gel autocombustion method. All compounds crystallize in an orthorhombic structure with Pbnm symmetry. X-ray diffraction confirms that GdMnO3 exhibits an O′-type structure, whereas Fe3+-doped and Fe3+/Al3+-codoped samples adopt an O-type structure. Magnetization measurements reveal that Fe substitution markedly increases the Néel temperature of the Mn/Fe sublattice from ~ 40 K in GdMnO3 to 293 K in GdMn0.5Fe0.5O3, and 232 K in GdMn0.5Fe0.25Al0.25O3, indicating enhanced superexchange interactions. The maximum magnetic entropy change (− ΔSₘ) occurs near 7.5 K, reaching ~ 19, ~ 18, and ~ 14 Jkg−1 K−1 under 5 T, respectively, primarily due to field-induced ordering of the Gd3+ sublattice. Conversely, the Mn/Fe sublattice transition near room temperature produces only a modest entropy change. Despite a reduction with co-doping, the magnetocaloric response remains notable among manganites, particularly in the cryogenic temperature range.

Graphical abstract