Cobalt hydroxide nitrate hydrate, Co(OH)(NO3).cntdot.H2O: a novel double-chain compound with competing interactions

Magnetic susceptibility and magnetization measurements of the newly synthesized cobalt(II) hydroxide nitrate Co(OH)(NO 3 )-H 2 O show that this system presents above 2.5 K a low-dimensional magnetic behavior. It is described in terms of Ising-like S=1/2 double chains with two nearest-neighbor exchange interactions, J 1 =22.8 K and J 2 =-9.75 K. The couplings between cobalt(II) ions are discussed using structural data for the in-chain and interchain exchange pathways