2008/04/08 by R. Nath, Deepa Kasinathan, H. Rösner +3
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Magnetism in coordination complexes #Physics of Superconductivity and Magnetism #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.77.134451
9 pages, 8 figures. Accepted in PRB 2008
arxiv created 2008/04/08 · openalex publication_date 2008/04/30 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The electronic and magnetic properties of K2CuP2O7 were investigated by means of susceptibility, specific heat and 31P nuclear magnetic resonance (NMR) measurements and by local density approximation (LDA) band structure calculations. The temperature dependence of the NMR shift K(T) is well described by the S=(1)/(2) Heisenberg antiferromagnetic chain (HAF) model with nearest neighbor exchange J1\ensuremath≃(141\ifmmode±\else\textpm\fi5)\phantom\rule0.3em0exK. The corresponding mapping of an LDA-derived tight-binding model leads to J1LDA\ensuremath≃196\phantom\rule0.3em0exK. The spin lattice relaxation rate 1/T1 decreases with temperature below 300\phantom\rule0.3em0exK but becomes nearly temperature independent between 30 and 2\phantom\rule0.3em0exK, as theoretically expected for an S=(1)/(2) HAF chain. None of the investigated properties give any evidence for long range magnetic order above 2\phantom\rule0.3em0exK, which is in agreement with the results of the band structure calculation, which yield extremely weak exchange to the next nearest neighbor and a very small and frustrated interchain exchange. Thus, K2CuP2O7 seems to be a better realization of a nearest neighbor S=(1)/(2) HAF chain than the compounds reported so far.