Semiconducting nature, magnetic critical exponent, and magnetocaloric effect study near room temperature on Fe[sbnd]Mn[sbnd]Al alloy.

• Atomic distribution is Fe 2.5 Mn 0.5 Al which is crystallized in B 2 phase of the Fm 3 ¯ m space group. • Curie temperature is at 280 K. Magnetic and Electrical phase transitions are occuring here. • Near room temperature this sample exhibit semiconducting nature of resistivity. • It is observed that there is a correlation between magnetic ordering and various temperature dependent scattering phenomena of electron. • The critical exponents are β = 0.48, γ = 1.11, and δ = 3.1. So, long range spin ordering is existing in the sample. The Fe 2.5 Mn 0.5 Al Heusler alloy, prepared by Arc melting method, crystallizes to B 2 in the Fm-3m space group. Resistivity measurement shows semi-metallic behavior in low temperature due to the dominance of magnon-magnon scattering and, exhibits semiconducting nature above the Curie temperature. Hence, it is predicted that there is a correlation between magnetic ordering and electrical transport properties. Arrott plot, Kouvel fisher method, and Widom scaling relation have been used here to determine the critical exponents. The Curie temperature (T C) is found to be near room temperature at 280 K. Also, critical exponents indicate that the magnetic ordering is following mean-field theory i.e., long-range interaction is present with 2nd order para to ferromagnetic transition. On the other hand, due to the 2nd order magnetic phase transition, significant magnetocaloric effect has been observed in a wide temperature range near room temperature. The maximum entropy change is found at 280 K i.e., at Tc. [ABSTRACT FROM AUTHOR]