Compensated Ferrimagnetism and Compensation Temperatures in Mn2-2 X Co0.5 X V0.5 X Ga Heusler Alloys

Abstract

Melt spun ribbons of Heusler alloys Mn 2-2 x Co 0.5+ x V 0.5+ x Ga ( x = 0, 0.1, 0.2, 0.25, 0.3, 0.4, 0.5) with 24 valence electrons were synthesized. Curie temperature decreases from 634 to 122 K with decreasing Mn content. Fully compensated ferromagnetic state was achieved for the x = 0.2 and x = 0.4 compositions. The compensation temperature, determined from the Hall resistivity measurements, was found to be ⁓130 K for the Mn 1.6 Co 0.7 V 0.7 Ga composition and ⁓317.5 K for the Mn 1.2 Co 0.9 V 0.9 Ga composition. Besides, a kink on the magnetization curves of the x = 0 – 0.4 compounds, observed at T ≈ 70 K, was suggested to be presumably due to a spin-reorientation transition.

Keywords: Heusler alloys, compensated ferrimagnets, compensation temperature, Mn2Co(V)Ga