MAGNETIC-PROPERTIES OF UTSN COMPOUNDS (T=CO, RH, IR, RU) STUDIED BY SN-119 MOSSBAUER-SPECTROSCOPY

Detailed Sn-119 Mossbauer studies were performed on the ferromagnetic uranium intermetallic compounds UTSn (T=Co, Rh, Ir, Ru) both above and below their Curie temperatures. The analysis of the experimental resu lts allowed to determine the direction of magnetization which coincide s with the crystallographic c axis for all these compounds as well as to define the orientations of the principal axes of the electric field gradient tensor with respect to the crystallographic axes. For UCoSn, URhSn, and UIrSn, the V-yy component is parallel to the c axis while in the case of URuSn, the V-zz component is parallel to this axis. The Mossbauer spectra taken at higher temperatures demonstrate a consider able distribution of magnitudes of the transferred magnetic hyperfine fields as well as a coexistence of magnetic and nonmagnetic contributi ons close to the Curie temperatures.