Nuclear magnetic relaxation of proton in an S = 1 Haldane gap linear chain system Ni(C₅H₁₄N₂)₂N₃(ClO ₄)

The nuclear magnetic relaxation T₁ of proton in a new Haldane gap system Ni(C₅H₁₄N₂)₂N₃(ClO ₄) has been measured in the temperature range between 2 and 60 K applying an external field up to about 7 T. Experimental results at low and high temperature ranges were interpreted in terms of relaxation mechanisms associated with the fractional spin and magnetic excitations, respectively. These features are essentially the same as those of NENP except for the fact that there is no appreciable field dependence at least up to 5 T.