High frequency ESR measurements of Co-delta chain

The δ-chain, which consists of a sawtooth chain with frustrated spin trimers, is expected to have various ground state and low-lying excitations due to their geometrical spin network. The model substance of δ-chain compound is [Co2(OH){1,2,3-(O2C)3C6H3}(H2O)]·(H2O), which consists of Co2+ δ-chain. In this system Co2+ ion behaves like the Ising spin due to its magnetic anisotropy. To investigate the dynamical properties of this δ-chain compound, high frequency ESR measurements have been performed using Gunn oscillators and BWO. Observed dynamical property of [Co2(OH){1, 2,3- (O2C)3C6H3}(H2O)] · (H2O) will be discussed.