Anisotropy of Magnetic and Transport Properties οf UAuSb₂Single Crystals

Abstract

The uranium-gold diantimonide UAuSb2 belongs to a numerous family of ternary compounds crystallizing in a tetragonal structure of the HfCuSi2-type (space group P 4/nmm). In this paper the results of magnetization, electrical resistivity and thermopower measured along the main crystallographic directions are reported. Two magnetic transitions, a ferromagnetic one at TC = 31 K and probably an antiferromagnetic one at TN = 43 K were found. The spontaneous magnetization at 1.9 K amounts about 0.8 µB for B c-axis. Electrical resistivity for j ⊥ c-axis exhibits a T 2 exp(−∆/kT ) dependence at low temperatures and a Kondo effect at higher temperatures above TN. The thermopower S for both main crystallographic directions shows a maximum at the temperature close to TC and the lack of any anomaly at TN.

X-ray photoemission spectrum, electronic structure, and magnetism of UCuxSb2

“…The fundamental physical properties of the ternary uranium diantimonides with the chemical formula UT x Sb 2 (x is some deficit of T atoms being Co, Ni, Cu and Au) have already been studied using monocrystalline materials [1][2][3][4]. These studies revealed their very strong anisotropy and substantial deficiency in the transition metal site occupancy of Co, Ni and Cu, similar to those found previously for their rare earth counterparts, e.g.…”

“…This probably concerns also UAuSb 2 , exhibiting in this series a full occupation of the Au layer, for which two magnetic transitions i.e. the ferromagnetic at T C = 31 K and antiferromagnetic at T N = 43 K, have been found [4]. Thus, the electronic band structure of this Au-based compound http has been calculated by the full potential linear muffin-tin orbital (LMTO) method [11].…”

Physical properties and field-induced metamagnetic transitions in UAu0.8Sb2

“…Table 1 shows the results of the refinement, while the atomic coordinates and occupancy factors are provided in Table 2 . The refined lattice parameters and unit cell volume are a = 0.436320(6) nm, c = 0.978574(3) nm and V = 0.1862963(6) nm 3 , which are smaller than those reported for UAuSb 2 ( a = 0.4375(1) nm, c = 0.9831(2) nm) 19 . Upon refining the site occupancies keeping those of the U site fixed to one, the Sb sites are very close to being fully occupied, but the occupancy of the Au site is 0.792(2).…”

“…The partially occupied UAu 0.8 Sb 2 shares some similarities to both UAuSb 2 and USb 2 . UAuSb 2 likely undergoes two magnetic transitions, a ferromagnetic one at T C = 31 K and a possible antiferromagnetic transition at T N = 43 K 19 . Meanwhile USb 2 undergoes an antiferromagnetic transition at 203 K, with no other magnetic transitions at lower temperature 20 .…”

Ab initio Calculations of the Magnetocrystalline Anisotropy in UAuSb2Ferromagnet

“…The conclusion from the both series of the band structure calculations is that the direction [111] is the easy axis of magnetization and the magnetocrystalline anisotropy is strong, the anisotropy constants K, K 2 are of the order of magnitude 16, 5-6 MJ/m 3 . Magnetic measurements on UAuSb 2 [11] indicate that this conclusion can be valid.…”