NMR Study of Ferromagnetism in V(Ir_1−xPt_x)₃

抄録

The zero-field NMR signal in magnetic V(Ir_1−xPt_x)₃ with the Cu₃Au-type structure has been observed in the frequency range of 10–80 MHz by spin echo method at 1.7 K. The peak of the spectrum which is attributable to the ⁵¹V nucleus has a nearly constant frequency ∼55 MHz for x≥0.69, corresponding to about −50 kOe. The dependence of the signal intensity on x is interpreted as follows; the V atoms have magnetic moments when the number of the nearest neighbor Pt atoms is more than about nine. Since the spontaneous magnetization decreases at larger x values, the antiparallel polarization to the V magnetic moment would be expected at Pt sites and would nearly cancel the V magnetic moment at x=1.0 (VPt₃). VPt₃ is thought to have a magnetic ordering below 206 K, at which the electrical resistivity has an anomaly.