We report on the results of a P 31 nuclear-magnetic-resonance (NMR) study on Cu2PO4OH at temperatures between 4 and 300 K. This material has been a subject of current interest due to indications of spin gap behavior. The temperature-dependent NMR shift exhibits a character of low-dimensional magnetism with a broad maximum at Tmax ≃ 110 K. Below Tmax, the NMR shifts and spin-lattice relaxation rates clearly indicate activated responses, confirming the existence of a spin gap in Cu 2PO4OH. The experimental NMR data can be well fitted to the square spin tetramer (SQST) model, yielding a spin gap size of about 140 K. It thus points out that the nearly isolated SQST picture is proper for the understanding of the spin gap nature in Cu2PO4OH.
|期刊||Physical Review B - Condensed Matter and Materials Physics|
|出版狀態||Published - 2008 12月 1|
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