%0 Journal Article
%A Bauer, A.
%A Regnat, A.
%A Blum, C. G. F.
%A Gottlieb-Schönmeyer, S.
%A Pedersen, B.
%A Meven, M.
%A Wurmehl, S.
%A Kuneš, J.
%A Pfleiderer, C.
%T Low-temperature properties of single-crystal CrB$_{2}$
%J Physical review / B
%V 90
%N 6
%@ 1098-0121
%C College Park, Md.
%I APS
%M FZJ-2015-00762
%P 064414
%D 2014
%X We report the low-temperature properties of 11B enriched single-crystal CrB2 as prepared from high purity Cr and B powder by a solid-state reaction and optical float-zoning. The electrical resistivity, ρxx, Hall effect, ρxy, and specific heat, C, are characteristic of an exchange-enhanced Fermi liquid ground state, which develops a slightly anisotropic spin gap Δ≈220~K below TN=88~K. This observation is corroborated by the absence of a Curie dependence in the magnetisation for T→ 0 reported in the literature. Comparison of C with dxx=dT , where we infer lattice contributions from measurements of VB2, reveals strong antiferromagnetic spin fluctuations with a characteristic spin fluctuation temperature Tsf≈257~K in the paramagnetic state, followed by a pronounced second order mean-field transition at TN, and unusual excitations around ≈TN/2. The pronounced anisotropy of ρxx above TN is characteristic of an easy-plane anisotropy of the spin fluctuations consistent with the magnetisation. The ratio of the Curie-Weiss to the Neel temperatures, f=−ΘCW/TN≈ 8.5, inferred from the magnetisation, implies strong geometric frustration. All physical properties are remarkably invariant under applied magnetic fields up to 14~T, the highest field studied. In contrast to earlier suggestions of local moment magnetism our study identifies CrB2 as a weak itinerant antiferromagnet par excellence with strong geometric frustration.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000341104600004
%R 10.1103/PhysRevB.90.064414
%U https://juser.fz-juelich.de/record/186690