Scholarlink

<p>MnCoGe-based magnetocaloric materials are typically limited by irreversibility and narrow operating temperature ranges arising from their characteristic first-order magneto-structural transitions. This study demonstrates that substituting Ni at the Ge site in MnCoGe<sub>0.9</sub>Ni<sub>0.1</sub> fundamentally alters the phase transition behavior, stabilizing a reversible second-order magnetic phase transition. The second-order nature is confirmed through multiple criteria, including the absence of thermal and magnetic hysteresis, positive slopes in Arrott plots, the universal behavior of the magnetic entropy change, and a detailed critical exponent analysis (β ≈ 0.42, γ ≈ 1.00, δ ≈ 3.36). As a consequence, the alloy exhibits a moderate yet fully reversible magnetocaloric effect, achieving a maximum magnetic entropy change of 3.86&#xa0;J/(kg·K) under a 7&#xa0;T field change, accompanied by negligible hysteresis loss and a competitive refrigeration capacity of 280&#xa0;J/kg enabled by a broad operating temperature window. These findings establish Ge-site Ni substitution as a practical route to low-hysteresis, reversible magnetocaloric materials, addressing the key limitations of MnCoGe-based systems and enabling more robust solid-state cooling performance.</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

Effect of Ge-site nickel substitution on the critical behavior and magnetocaloric properties of MnCoGe

  • 期刊论文

  • 发表日期：

    2026年6月15日

查看全文
  • Hao Chen,
  • Zhenhao Chu

摘要

MnCoGe-based magnetocaloric materials are typically limited by irreversibility and narrow operating temperature ranges arising from their characteristic first-order magneto-structural transitions. This study demonstrates that substituting Ni at the Ge site in MnCoGe0.9Ni0.1 fundamentally alters the phase transition behavior, stabilizing a reversible second-order magnetic phase transition. The second-order nature is confirmed through multiple criteria, including the absence of thermal and magnetic hysteresis, positive slopes in Arrott plots, the universal behavior of the magnetic entropy change, and a detailed critical exponent analysis (β ≈ 0.42, γ ≈ 1.00, δ ≈ 3.36). As a consequence, the alloy exhibits a moderate yet fully reversible magnetocaloric effect, achieving a maximum magnetic entropy change of 3.86 J/(kg·K) under a 7 T field change, accompanied by negligible hysteresis loss and a competitive refrigeration capacity of 280 J/kg enabled by a broad operating temperature window. These findings establish Ge-site Ni substitution as a practical route to low-hysteresis, reversible magnetocaloric materials, addressing the key limitations of MnCoGe-based systems and enabling more robust solid-state cooling performance.