Nuclear Spin-Lattice Relaxation Due to Domain Wall Solitons in CsCoCl3

Nuclear spin-lattice relaxation of 133 Cs has been studied in the frustrated antiferromagnet, CsCoCl 3 . A pronounced anomaly in the relaxation rate was observed at the lower transition temperature, T N2 =10 K, whereas a weak change in the relaxation rate was observed at the upper transition temperature, T N1 =21 K. The results are discussed in terms of the characteristic dynamics of domain wall solitons which propagate in disordered magnetic chains which feel no molecular field from the neighboring chains.