A comparative study of structural, electronic, magnetic, and pressure-dependent properties of Full-Heusler Fe<sub>2</sub>XSi (X=Mn and Co): first-principles calculation and Monte Carlo Simulation
Bilal Aladerah, Maen Gharaibeh, Abdalla Obeidat, Khaled Aledealat
Abstract
Abstract This study investigates the structural, electronic, magnetic, and pressure-dependent properties of Fe 2 XSi (X=Mn and Co) full-Heusler alloy through a comprehensive computational approach. The structural stability of these alloys confirmed L2 1 and XA prototypes as favorable structures for Fe 2 MnSi and Fe 2 CoSi, respectively. In addition, Fe 2 MnSi exhibits 100% spin polarization suggesting its potential suitability for spintronics applications. Conversely, Fe 2 CoSi does not exhibit similar behavior. The calculated magnetic moments of these alloys revealed an increase due to Coulomb interaction (U). The magnetic moments satisfy the Slater-Pauling relation, with calculated values of 3 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>μ</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>B</mml:mi> </mml:mrow> </mml:msub> </mml:math> for Fe 2 MnSi and 5 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>μ</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>B</mml:mi> </mml:mrow> </mml:msub> </mml:math> for Fe 2 CoSi. Heisenberg exchange interaction parameters are calculated to illustrate distinct magnetic interactions within the alloys. The study further explores thermomagnetic properties through Monte Carlo simulations, including thermal magnetization, thermal magnetic susceptibility, and Curie temperature <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mfenced close=")" open="(" separators=""> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>T</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>C</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:mfenced> <mml:mo>.</mml:mo> </mml:math> The calculated <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>T</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>C</mml:mi> </mml:mrow> </mml:msub> </mml:math> were found to be 294 K for Fe 2 MnSi and 1029 K for Fe 2 CoSi, showing close agreement with experimental data. We additionally investigate the pressure-dependent properties of these alloys, revealing a non-linear dependence of the band gap on pressure for Fe 2 MnSi, with values decreasing from 0.668 eV to 0.259 eV as pressure increased from −15.917 to 23.712 GPa. For Fe 2 CoSi, the band gap remained zero across varying pressure conditions, indicating its metallic conducting behavior.