Co10Ge3O16

The structure of a new cobalt germanate, Co10Ge3O16, has been determined using X-ray diffraction data collected on a single crystal grown by slow cooling of a stoichiometric melt at atmospheric pressure. Co10Ge3O16 is isostructural with (Ni,Mg)10Ge3O16 and is also structurally related to the mineral aerugite, Ni8.5As3O16. Its crystal structure is based on a cubic close-packing of O atoms with octahedral (Co and Ge) and tetrahedral (Ge) metal-atom sites. It can be described as an intergrowth of {111} spinel triple layers with {111} rock-salt single layers along the [001]hex direction of the rhombohedral cell. (orig.)