A new non-Fermi-liquid-like layered Cr boride

We report the discovery, the synthesis of large high quality single crystals, the crystal structure, and the basic properties of Cr₄AlB₄, a new member of the electrically conductive and damage tolerant MAB phase borides. Cr₄AlB₄ forms in a new orthorhombic structure-type in which slabs of Cr-B containing zig-zag chains of B are separated by nearly square planes of Al. Electrical resistivity measurements along the chain direction show a non-Fermi-liquid-like T³-dependence up to T ≈ 80 K, before becoming linear above T ≈ 150 K . We discuss these results in terms of magnetic and spectroscopic measurements and place this compound within the context of layered and quasi-one dimensional Cr-based systems.