Quasi-one-dimensional behavior of (CH3)2NH2MnCl3 (DMMC)

The heat capacity of dimethyl ammonium manganese trichloride has been investigated for 1.6<T<50 K. A transition to a three-dimensional antiferromagnetically ordered state has been observed at 3.60 K, which is supported by nuclear-magnetic-resonance and susceptibility measurements. The critical entropy did amount to 3.4%. The magnetic heat capacity in the paramagnetic region could be described very well by a S=52 Heisenberg linear chain system with Jk=-5.8±0.7 K. The data for kT|J|<1.5, together with the earlier data on (CH3)4NMnCl3, corroborate the suggested low-temperature behavior of such a system.