Abstrakt
A new U-based compound of the U2Rh2Pb, a new compound of the U2T2X series (T - transition metal, X - Sn, In, Pb), was prepared in a single-crystal form. Its structure was determined as belonging to the tetragonal Mo2FeB2 structure type with the shortest U-U spacing along the c-axis.
The crystals were subjected to study of magnetic, specific heat, and electrical resistivity in various magnetic fields. U2Rh2Pb undergoes an antiferromagnetic transition at a Neel temperature T-N of 20 K and exhibits an enhanced Sommerfeld coefficient gamma approximate to 150 mJ/molK(2).
In contrast to the two rhodium analogues U2Rh2In and U2Rh2Sn, the easy-magnetization direction is the c-axis with rather low value of the critical field H-c = 4.3 T of the metamagnetic transition of a spin-flip type. The observed dependences of T-N and H-c on temperature and magnetic field have been used for constructing a magnetic phase diagram.
The experimental observations are mostly supported by first-principles calculations. (C) 2019 Published by Elsevier B.V.