Magnetic phase diagram of the antiferromagnet U2Rh2Pb

Abstract

A new U-based compound of the U2Rh2Pb, a new compound of the U2T2X series (Ttransition 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 caxis. The crystals were subjected to study of magnetic, specific heat, and electrical resistivity in various magnetic fields. U2Rh2Pb undergoes an antiferromagnetic transition at a Néel temperature TN of 20 K and exhibits an enhanced Sommerfeld coefficient   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 Hc = 4.3 T of the metamagnetic transition of a spin-flip type. The observed dependences of TN and Hc on temperature and magnetic field have been used for constructing a magnetic phase diagram. The experimental observations are mostly supported by first-principles calculations.

Ui3 – 5f-Electron Magnetic Van Der Waals Material

“…The peak-like anomaly at the AFM transition in specific heat data responds to the external magnetic field in agreement with the gradual vanishing of the metamagnetic transition. In ordinary antiferromagnets, a paramagnetic-like response of the temperature dependence of specific heat is detected for fields H > Hc [50,51]. Broad knees have been observed in specific heat data both for the a-and b-axis in the curves recorded for magnetic fields H > Hc(a,b).…”