Nearly antiferromagnetic metal with linear spin chains: LaMn4Al8

Magnetic properties of the tetragonal ThMn12-type LaMn4Al8 were investigated to get information on the origin of the large temperature-linear term of the low- temperature specic heat (γ=265 mJ/K2 mol) of this compound. The susceptibility obeys the modified Curie–Weiss law with a small effective moment at high temperatures and shows a broad maximum at around 5 K. The 27Al nuclear spin-lattice relaxation rate shows the typical temperature dependence for the nearly antiferromagnetic metal. The one-dimensional-like arrangement of Mn atoms is emphasized as one of the characteristics of this compound.