Effects of Short Range Spin Correlation on ESR Lines of Low-Dimensional Antiferromagnetic and Spin-Gapped Systems

摘要: ESR measurements have been performed on (CH 3 ) 4 NMnCl (TMMC) and Cu 1- x Zn Nb 2 O 6 with varying temperature T down to the region where significant spin correlation can be observed. For TMMC which is a typical example of systems quasi-one-dimensional chains, linewidth Δ H pp dynamical shift, resonance-field-shift depends direction microwave field increase similarly decreasing below ∼ 0 , uniform magnetic susceptibility has maximum. Zn-doped crystal monoclinic CuNb spin-gapped ground state, shift exhibit similar decrease ∼Δ/ k B spin-gap energy. orthorhombic not observed at room temperature. Rather large value in -region antiferromagnetic suggests that it becomes important discussi...