Temperature dependent partially compensated to nearly fully compensated magnetic state in half-metallic full Heusler alloy, Mn1.2Fe1.18V0.62Al

We report experimental and theoretical studies of magnetization compensation phenomenon in quaternary Heusler alloy Mn1.2Fe1.18V0.62Al by employing dc magnetization, neutron depolarization, neutron diffraction, specific heat, electrical resistivity, and electronic structure calculation. In this ferrimagnetic alloy system with ordering temperature TC = 360 K, the asymmetric thermal variations of the site magnetic moments provide an evidence of the partially compensated magnetic state of the system down to 48 K. However, below similar to 48 K, the system exhibits its magnetic ground state with the negligibly small ordered moment of 0.05(5) mu(B)/f.u. at 10 K, as obtained from the neutron diffraction study. Nearly full recovery of neutron beam polarization at 4 K in the neutron depolarization study also infers a nearly fully compensated magnetization state in this Heusler alloy. Temperature dependent specific heat and resistivity measurements also corroborate with the dc magnetization study representing 48 K as a turning point at which the system reaches its ground state. The electronic structure calculations, using the SPR-KKR Green's function approach, verify the half- metallic nature of the present system. The net magnetic moment (0.06 mu(B)/f.u.) obtained from the theoretical calculations as well as neutron diffraction experiments (0.05 mu(B)/f.u.) is in good agreement with the Slater-Pauling rule (0.06 mu(B)/f.u.). This small magnetic moment of the system (Mn0.82Fe1.18)(Mn0.38V0.62)Al proclaims to be a nearly compensated ferrimagnetic system with 23.94 valence electrons. Such magnetically compensated systems with finite spin polarization could be favorable for spintronics applications.

Automated summary

This study reports experimental and theoretical investigations on the magnetization compensation phenomenon in the quaternary Heusler alloy Mn1.2Fe1.18V0.62Al. The results demonstrate that this alloy exhibits a nearly fully compensated magnetization state below 48 K. Furthermore, electronic structure calculations confirm its half-metallic nature. Such nearly compensated magnetic systems could be favorable for spintronics applications.