Anisotropies of the electrical resistivity and Hall effect in UAsSe

Electrical transport properties of USbSe and USbTe

“…Additionally, yet in the case of UPS and UAsSe only, below about 0.5T C the resistivity exhibits an anomalous upturn towards low temperatures [6,7,9]. This latter feature has recently attracted much attention being interpreted [6,9,10] in terms of non-magnetic Kondo effect in a two-level-system (TLS) scenario [11]. It was argued that the Kondo-like resistivity behavior arises in UPS and UAsSe due to anion disorder, i.e.…”

Kondo phenomena of structural defects in USbTe ferromagnet

“…The first term is described by the well known the Bloch-Grüneisen (B-G) formula while the second term, representing the OK scattering, is described here by Arai given formula [13]. This formula was found previously [3] to describe well ρ K (T) in UAsSe ferromagnet characterized by T C = 102 K at temperatures 4.2 ÷ 430 K. Here the sum of resistivity components xρ ph + yρ K + ρ 0 was fitted to the ∆ρ(T) curve at T > T C = 123.4 K and extrapolated to the low temperature range as shows the curve 1 in Fig. 3.…”

“…Here we used the best- fitted value of C equal to 2.15. This method is a generalization of earlier approach applied for resolving of UAsSe resistivity into their magnetic, Kondo and phonon contributions [3]. The determined ∆ρ(T) dependence is composed of two temperature dependent terms: ∆ρ ph = ( c ρ ph -2.15 a ρ ph ) ~ xρ ph (T) and…”

“…Thus, UAsSe can be considered as the first HF-like system in which ferromagnetism coexist with the OK effect. The low-T upturn in ρ(T) and low-T peak in S(T) deep in the ferromagnetic state [3,4,6] are clear signs of the Kondo problem in UAsSe.…”

“…Previous work on the structurally disordered UAsSe ferromagnet [3] has demonstrated that its temperature dependence of the electrical resistivity ρ(T) could be resolved into magnetic, Kondo, phonon and residual contributions. Recent studies [4] showed that a variation in the As-Se chemical composition affects the low-T thermoelectric power S(T) of UAsSe in similar way as the Ce +3 concentration does in the paramagnetic heavy-fermion (HF) system Ce x Y 1-x Cu 2.05 Si 2 [5].…”