NMR Study of Coexistence of Ferro- and Antiferromagnetism in the Itinerant Electron System (Zr_1−xNb_x)Fe₂. I

Abstract

Pulsed NMR investigations of ⁹³Nb have been performed in the hexagonal Laves phase intermetallic compound (Zr_1−xNb_x)Fe₂ with 0.8≤x≤1.0. From the measurements of the Knight shift and the nuclear spin-lattice relaxation time T₁, it is demonstrated that NbFe₂ is a nearly ferromagnetic compound and (Zr_1−xNb_x)Fe₂ with x=0.95 and 0.85 are weakly ferromagnetic compounds having a Curie temperature of 30 K and 40 K, respectively, in contrast with the itinerant electron antiferromagnetism for 0.5≤x≤0.7. In the composition of x=0.8 where the antiferromagnetic order occurs below 85 K and ferromagnetic moment appears below 30 K, it was found out from T₁ measurement that the system is in a coexistent state of ferro- and antiferromagnetism.