Ga nuclear magnetic resonance study of UTGa(T=Ni, Pt)

Kato, Harukazu; Sakai, Hironori; Tokunaga, Yo  ; Tokiwa, Yoshifumi; Ikeda, Shugo; Onuki, Yoshichika; Kambe, Shinsaku  ; Walstedt, R. E.

UPtGa and UNiGa are 5-itinerant antiferromagnets with Nel temperature = 26 K (Pt), 86 K (Ni). Remarkably, although the two compounds show almost identical Fermi surface properties in the paramagnetic state, recent neutron scattering experiments reveal that UPtGa and UNiGa are quite different in magnetic structure below . In the microscopic viewpoint, we have carried out Ga NMR/NQR measurements for the both coumpounds. We have suceeded in separating the temperature independent term and the Curie-like-temperature-dependent term of the Knight shift . This should be a good starting point in considering the magnetism of this system.