Metal to semimetal transition and magnetic critical behavior at room temperature in the full Heusler alloy Fe2MnSi.

The crystal structure, magnetic and electrical transport properties of Fe2MnSi Heusler alloy have been investigated in the present study. It is found that the sample has been crystallized to the Fmm space group in the L21 structure. Ferromagnetic to paramagnetic phase transition (Curie temperature) has been observed at around 325 K, which is further confirmed by employing the Arrott plot technique. Critical exponent values () have been obtained by employing the Kouvel–Fisher method and Widom-scaling relation; confirming the second order phase transition observance in the magnetic transition region. These values suggest that the magnetic transition follows the mean field theory. Furthermore, the electrical resistivity and spontaneous magnetization data analysis in the low-temperature region ensures the presence of magnon in the system. Detailed analysis of the resistivity data for 50 K to 400 K reveals a metal to semimetal transition at around 325 K, which is close to the Curie temperature. A correlation between electrical transport and magnetic ordering has been observed in the Fe2MnSi alloy. [ABSTRACT FROM AUTHOR]