U Mssbauer study on the 5f-quadrupoles in uranium-based intermetallics

Tsutsui, Satoshi*; Nakada, Masami; Nasu, Saburo*; Homma, Tetsuo*; Tokiwa, Yoshifumi; Aoki, Dai*; Wisniewski, P.*; Haga, Yoshinori; Onuki, Yoshichika

Hyperfine Interactions, 141/142(1-4), p.237 - 242, 2002/06

https://doi.org/10.1023/A:1021281315015

We have determined the distribution of the 5f-quadrupoles and detected the 5f-quadrupole order in the uranium intermetallics, uranium dipnictides and UPd, with Mo"ssbauer spectroscopy. We have declared that the distribution of the 5f-quadrupoles depends on the magnetic sequence in uranium dipnictides. The distribution of the 5f-quadrupole is spherical in UBi, while those are oblate within c-plane in UP, UAs and USb. We have observed the sudden drop of the recoil-free fraction above the transition temperature of the quadrupole order in UPd. The present result suggests the change of the phonon states due to the quadrupole order in this compound.