NMR study of quasi-two-dimensional antiferromagnet Cs2CuBr4

摘要: Abstract 133 Cs -NMR experiments on the S= 1 2 quasi-two-dimensional antiferromagnet Cs2CuBr4 have been performed up to magnetic fields of 15.9 T , which covers field range for 3 magnetization plateau. Outside plateau region, NMR spectrum at T=0.5 K shows a double-horn type broad line shape characteristic an incommensurate spin structure. On other hand, discrete two peaks were observed in phase, indicating commensurate up–up–down The nuclear spin–lattice relaxation rate T1−1 phase decreases much more steeply with decreasing temperature than that indicates different low lying excitations phases. Experimental results paramagnetic are also discussed.