Magnetic Properties of (Cr_1-xNi_x)₂As Single Crystal Compounds

Abstract

Measurements of magnetization and susceptibility were made on the hexagonal (Cr 1- x Ni x ) 2 As single crystal compounds. The compounds were antiferromagnetic for 0.4< x ≤0.45 and ferromagnetic for 0.45< x ≤0.7. The concentration dependences of the magnetic transition temperature, the saturation magnetization and the second order anisotropy constant at 4.2 K show maxima of 188 K ( T c ), 1.19 µ B per formula unit and 1.46×10 6 erg/cm 3 at x =0.5, respectively. The Curie constant is independent of x for 0.375≤ x ≤0.5, while it decreases with increasing x for x >0.5. The magnetization curves in the antiferromagnetic compounds at 4.2 K have relatively low critical fields. The compound of x =0.425 shows an unusual magnetization curve. The results were briefly discussed on the basis of the theory of spin fluctuations.