posted on 2024-02-26, 13:05authored byN. Zaremba, M. Krnel, Yu. Prots, M. König, L. Akselrud, Yu. Grin, E. Svanidze
This work presents
a study on a new uranium iron arsenide UFe5As3. By implementing Bi-flux synthesis, we were
able to grow mm-sized single crystals of this compound, which show
twinning. UFe5As3 is one of only two known uranium
iron arsenides. It adopts a monoclinic, UCr5P3-type crystal structure (space group P21/m, Pearson symbol mP18, a = 7.050(2) Å, b = 3.8582(9) Å, c = 9.634(1) Å, β = 100.25(1)°). The magnetic
susceptibility of UFe5As3 indicates it to be
an antiferromagnet with TN = 47 K and
μeff = 4.94 μB per formula unit,
signaling that both U and Fe are likely magnetic in this material.
The material appears to be anisotropic, with a small (likely ferromagnetic)
spin reorientation transition around T = 29 K. The
Sommerfeld coefficient γ0 = 135 mJ mol–1 K–2 suggests enhanced effective electron mass
in UFe5As3, while electrical resistivity indicates
metallic, Kondo-like behavior.