Quasi‐one‐dimensional S = 1/2 magnet Pb[Cu(SO₄)(OH)₂]: frustration due to competing in‐chain exchange

Abstract

Abstract Zero‐field susceptibility and specific heat of Pb[Cu(SO 4 )(OH) 2 ] (linarite) single crystal were measured. In order to verify that linarite is a quasi‐one‐dimensional system with competing nearest‐neighbour and next‐nearest‐neighbour in‐chain exchange interaction ( J 1 ≈ –30 K, J 2 ≈ 15 K), theoretical results based on electronic structure calculations within the LDA and a phenomenological modelling using the finite‐temperature transfer‐matrix method are taken into account. The possibility of various ground states is discussed in terms of the screened onsite repulsion U s : commensurate Neel or spin‐Peierls phases versus incommensurate spiral states with acute or obtuse pitch angles. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)