<p>The structural, elastic, electronic, magnetic, and magnetocaloric properties of the quaternary Heusler alloy CoFeMnSi were investigated using ab initio calculations based on density functional theory, as implemented in the SIESTA code, complemented by Monte Carlo simulations. The magnetic exchange interactions were determined using the TB2J code within the framework of the Heisenberg model, while finite-temperature magnetic properties were examined through Monte Carlo simulations. The electronic and magnetic analyses show that this material exhibits ferromagnetic behavior with half-metallic characteristics and a total magnetic moment of approximately <InlineEquation ID="IEq1"> <EquationSource Format="TEX">$4.0\mu{B}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mn>4.0</mn> <mi>μ</mi> <mi>B</mi> </mrow> </math></EquationSource> </InlineEquation> per formula unit. The results confirm that CoFeMnSi undergoes a second-order magnetic phase transition characterized by a Curie temperature of about <InlineEquation ID="IEq2"> <EquationSource Format="TEX">$608 K$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mn>608</mn> <mi>K</mi> </mrow> </math></EquationSource> </InlineEquation>. For a magnetic field variation ranging from 0 to <InlineEquation ID="IEq3"> <EquationSource Format="TEX">$10 T$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mn>10</mn> <mi>T</mi> </mrow> </math></EquationSource> </InlineEquation>, the maximum values of the magnetic entropy change, adiabatic temperature change, and relative cooling power reach approximately <InlineEquation ID="IEq4"> <EquationSource Format="TEX">$- \Delta S_{m} \approx 1.1 J .kg^{ - 1} .K^{ - 1}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mo>-</mo> <mi mathvariant="normal">Δ</mi> <msub> <mi>S</mi> <mi>m</mi> </msub> <mo>≈</mo> <mn>1.1</mn> <mi>J</mi> <mo>.</mo> <mi>k</mi> <msup> <mi>g</mi> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> <mo>.</mo> <msup> <mi>K</mi> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> </mrow> </math></EquationSource> </InlineEquation>, <InlineEquation ID="IEq5"> <EquationSource Format="TEX">$\Delta {T}_{ad} \approx 1.25 K$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi mathvariant="normal">Δ</mi> <msub> <mi>T</mi> <mrow> <mi mathvariant="italic">ad</mi> </mrow> </msub> <mo>≈</mo> <mn>1.25</mn> <mi>K</mi> </mrow> </math></EquationSource> </InlineEquation>, and <InlineEquation ID="IEq6"> <EquationSource Format="TEX">$RCP \approx 7J.K^{ - 1}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>R</mi> <mi>C</mi> <mi>P</mi> <mo>≈</mo> <mn>7</mn> <mi>J</mi> <mo>.</mo> <msup> <mi>K</mi> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> </mrow> </math></EquationSource> </InlineEquation>, respectively. These results highlight the strong potential of CoFeMnSi as a promising candidate for magnetic refrigeration and high-temperature spintronic applications.</p>

DFT and Monte Carlo study of the structural, elastic, electronic, magnetic, and magnetocaloric properties of the quaternary heusler alloy CoFeMnSi for magnetic refrigeration applications

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2026年6月23日

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Z. Elmghabar,
M. Ouasti,
S. Harir,
L. B. Drissi

摘要

The structural, elastic, electronic, magnetic, and magnetocaloric properties of the quaternary Heusler alloy CoFeMnSi were investigated using ab initio calculations based on density functional theory, as implemented in the SIESTA code, complemented by Monte Carlo simulations. The magnetic exchange interactions were determined using the TB2J code within the framework of the Heisenberg model, while finite-temperature magnetic properties were examined through Monte Carlo simulations. The electronic and magnetic analyses show that this material exhibits ferromagnetic behavior with half-metallic characteristics and a total magnetic moment of approximately $4.0\mu{B}$ $4.0 μ B$ per formula unit. The results confirm that CoFeMnSi undergoes a second-order magnetic phase transition characterized by a Curie temperature of about $608 K$ $608 K$ . For a magnetic field variation ranging from 0 to $10 T$ $10 T$ , the maximum values of the magnetic entropy change, adiabatic temperature change, and relative cooling power reach approximately $- \Delta S_{m} \approx 1.1 J .kg^{ - 1} .K^{ - 1}$ $- Δ S_{m} \approx 1.1 J . k g^{- 1} . K^{- 1}$ , $\Delta {T}_{ad} \approx 1.25 K$ $Δ T_{ad} \approx 1.25 K$ , and $RCP \approx 7J.K^{ - 1}$ $R C P \approx 7 J . K^{- 1}$ , respectively. These results highlight the strong potential of CoFeMnSi as a promising candidate for magnetic refrigeration and high-temperature spintronic applications.