Universität Bonn - "2D-Metals with locked charge density wave, in the novel layered monophosphate tungsten bronzes [Ba(PO₄)₂]W_mO_3m-3"⠀

We have synthesized a whole novel structural branch of mixed-valent, layered barium tungsten monophosphate bronzes (so-called L-MPTB*) with the general formula [Ba(PO₄)₂][W_mO_3–m] (m = 3 (W^5.33+), 4 (W^5.50+), and 5 (W^5.60+)). The structures are build from spacer-layers [Ba(PO₄)₂]^4‒ and separating ReO₃-like layers of variable thickness. The spacers guarantee a “genuine” 2D-behavior, and enforce an overall trigonal structure preserved down to 1.8 K for the whole series. The L-MPTB* display some analogies but also major differences in comparison to the long.known MPTBs. [...]