Magnetic phase diagram of the antiferromagnet U2Rh2Pb

• Published in: Journal of alloys and compounds Vol. 823; p. 153485
• Main Authors: Pospíšil, J., Míšek, M., Diviš, M., Dušek, M., de Boer, F.R., Havela, L., Custers, J.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15-05-2020; Elsevier BV
• Subjects: Antiferromagnet; Antiferromagnetism; Critical field (superconductivity); Crystal structure; First principles; Lead; Magnetic fields; Magnetocrystalline anisotropy; Metamagnetic transition; Phase diagram; Phase diagrams; Rhodium; Single crystals; Tin; Transition metals; U2Rh2Pb; U2T2X; U2T2X; Magnetocrystalline anisotropy; Antiferromagnet; Phase diagram; Metamagnetic transition; U2Rh2Pb
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2019.153485

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 Néel temperature TN of 20 K and exhibits an enhanced Sommerfeld coefficient γ ≈ 150 mJ/molK2. 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.
We have prepared single crystals of a new compound U2Rh2Pb. Our research represents first single crystals study of lead compound in the U2T2X series. Figure shows the magnetic phase diagram of U2Rh2Pb. Antiferromagnet U2Rh2Pb is unique by unusual easy magnetization direction, the lowest value of the magnetic field inducing metamagnetic transition combined with very simple magnetic phase diagram. [Display omitted]