Syntheses, structures and properties of metal phosphates PbMg(PO), PbZn(PO) and α-BaZn(PO).

PbMg(PO), PbZn(PO) and α-BaZn(PO) have been synthesized by the standard solid-state reaction and their structures were determined by single crystal X-ray diffraction for the first time. PbMg(PO), PbZn(PO) and α-BaZn(PO) crystallize in the monoclinic crystal system, P2/c, C2/c and the trigonal crystal system, P3[combining macron]m1, respectively. The structure of PbMg(PO) possesses a three-dimensional framework consisting of MgO octahedra and PO tetrahedra and the Pb cations reside in the [MgPO] tunnels. PbZn(PO) and α-BaZn(PO) are two-dimensional layered structures with [ZnPO] layers for PbZn(PO) and [ZnPO] honeycomb double layers for α-BaZn(PO). And in the structure of PbZn(PO), there are four different Zn-P-O layers, which is reported for the first time in zinc phosphates. In addition, thermal property analysis, and UV-Vis-NIR diffuse reflectance and infrared spectroscopy were also performed. First-principles theoretical studies were also conducted to aid the understanding of their band structures and densities of states.