The two-legged spin ladder Cu(CO3)0.5(ClO4)(H2O)0.5(NH3)2.5 consists of a rung formed by two Cu(II)’s and of a spacing molecule CO32− between each two rungs. The non-centrosymmetric shape of CO32− molecule brings a slight bond alternation along the leg, and hence the system can be considered as an alternating spin chain, which is confirmed so far by the temperature dependence of magnetic susceptibility. In order to investigate its spin state at low temperatures, we have performed experiments of 1H-NMR, magnetization and specific heat under wide range of magnetic field, and have found the critical diverging of longitudinal relaxation rate 1/T1, the spectral broadening and the lambda-type anomaly in specific heat at TN≃ 3.4 K, indicating the existence of long range magnetic order. In paramagnetic state well above TN, 1/T1 showed a power-law temperature dependence, suggesting the realization of Tomonaga Luttinger liquid state.
- Alternating spin chain
- Tomonaga-Luttinger liquid
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Nuclear and High Energy Physics
- Condensed Matter Physics
- Physical and Theoretical Chemistry