Spin gap in the single spin-1/2 chain cuprate Sr1.9Ca0.1CuO3 | |
Article | |
关键词: HEISENBERG ANTIFERROMAGNETIC CHAIN; CHARGE SEPARATION; COMPOUND SRCUO2; NMR RELAXATION; SR2CUO3; MAGNETIZATION; SR14CU24O41; DYNAMICS; | |
DOI : 10.1103/PhysRevB.89.184410 | |
来源: SCIE |
【 摘 要 】
We report Cu-63 nuclear magnetic resonance and muon spin rotation measurements on the S = 1/2 antiferromagnetic Heisenberg spin chain compound Sr1.9Ca0.1CuO3. An exponentially decreasing spin-lattice relaxation rate T-1(-1) indicates the opening of a spin gap. This behavior is very similar to what has been observed for the cognate zigzag spin chain compound Sr0.9Ca0.1CuO2, and it confirms that the occurrence of a spin gap upon Ca doping is independent of the interchain exchange coupling J'. Our results therefore suggest that the appearance of a spin gap in an antiferromagnetic Heisenberg spin chain is induced by a local bond disorder of the intrachain exchange coupling J. A low-temperature upturn of T-1(-1) evidences growing magnetic correlations. However, zero-field muon spin rotation measurements down to 1.5 K confirm the absence of magnetic order in this compound, which is most likely suppressed by the opening of the spin gap.
【 授权许可】
Free