31P NMR study of Na2CuP2O7: an S = 1/2 two dimensional Heisenberg antiferromagnetic system

R. Nath, A. V. Mahajan, N. Büttgen, Christian Kegler, J. Hemberger, A. Loidl

    Research output: Contribution to journalArticlepeer-review

    7 Citations (Scopus)

    Abstract

    The magnetic properties of Na2CuP2O7 were investigated by means of P-31 nuclear magnetic resonance (NMR), magnetic susceptibility, and heat capacity measurements. We report the 31P NMR shift, the spin-lattice (1/T-1), and spin spin (1/T-2) relaxation rate data as a function of temperature T. The temperature dependence of the NMR shift K(T) is well described by the S = 1/2 square lattice Heisenberg antiferromagnetic model with an intraplanar exchange of J/k(B) similar or equal to 18 +/- 2 K and a hyperfine coupling A = 3533 +/- 185 Oe/mu B. The P-31 NMR spectrum was found to broaden abruptly below T similar to 10 K, signifying some kind of transition. However, no anomaly was noticed in the bulk susceptibility data down to 1.8 K. The heat capacity appears to have a weak maximum around 10 K. With decrease in temperature, the spin-lattice relaxation rate 1/T-1 decreases monotonically and appears to agree well with the high temperature series expansion expression for a S = 1/2 2D square lattice.

    Original languageEnglish
    Pages (from-to)4285-4294
    Number of pages10
    JournalJournal of Physics: Condensed Matter
    Volume18
    DOIs
    Publication statusPublished - 2006

    Keywords

    • NUCLEAR MAGNETIC-RELAXATION
    • QUANTUM ANTIFERROMAGNETS
    • GROUND-STATES
    • SUSCEPTIBILITY
    • LA2CUO4
    • KCUF3

    Cite this