Magnetic and structural properties of Co$_2$MnSi based Heusler compound

TL;DR

This study investigates how antisite disorder affects the magnetic and transport properties of Co$_2$MnSi Heusler compounds using experimental and computational methods, revealing disorder-induced magnetic moment reduction and persistent positive magnetoresistance.

Contribution

It provides a combined experimental and theoretical analysis of antisite disorder effects on magnetic properties in Co$_2$MnSi, highlighting the impact on magnetic moments and transport behavior.

Findings

Mn and Co disorders are approximately 6.5 ext{-}7.6",

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Abstract

The influence of antisite disorder occupancies on the magnetic properties of the half-metallic Co$_2$MnSi compound was studied by experimental techniques and first-principles calculations. The neutron diffraction studies show almost identical amount of Mn and Co disorders of 6.5\% and 7.6\%, which was found to be in good agreement with density functional theory (DFT) calculations of the stable Co$_2$MnSi system with the corresponding disorders. DFT studies reveal that antiferromagnetic interactions introduced by Mn disorder lead to a reduction of the net magnetic moment. The results are discussed in conjunction with neutron diffraction and magnetization measurements. Transport property measurement under magnetic field up to 9 Tesla revealed a positive magnetoresistance for bulk Co$_2$MnSi that persists up to room temperature. A Curie temperature of $\sim$1014 K was determined for the compound by high temperature electrical resistivity and dilatometry measurements.