Low temperature magnetism of gapless S=1 bond-alternating antiferromagnet studied by NMR and SR

Kikuchi, Hikomitsu*; Chiba, Meiro*; Fujii, Yutaka*; Yamamoto, Yuji*; Higemoto, Wataru  ; Nishiyama, Kusuo*

H NMR and SR measurements on Ni(333-tet) (-N) (ClO), a gapless S=1 Heisenberg antiferromagnet with bond alternation, are measured. The spin lattice relaxation rate has anomaly at around 3 K without divergent behavior. The time spectra of SR are measured down to 1.7 K. A fast relaxation component develops below about 3 K, suggesting an occurrence of magnetic ordering. However, the ordering is found to have dynamical nature, since recovery of the asymmetry by applying longitudinal field was not observed.