The type IV polymorph of KEu(PO3)4

oleh: Daniel Zambon, Daniel Avignant, Boumediene Tanouti, Abdelghani Oudahmane, Mohamed Daoud

Format: Article
Diterbitkan: International Union of Crystallography 2009-12-01

Deskripsi

Single crystals of KEu(PO3)4, potassium europium(III) polyphosphate, were obtained by solid-state reactions. This monoclinic form is the second polymorph described for this composition and belongs to type IV of long-chain polyphosphates with general formula AIBIII(PO3)4. It is isotypic with its KEr(PO3)4 and KDy(PO3)4 homologues. The crystal structure is built of infinite helical chains of corner-sharing PO4 tetrahedra with a repeating unit of eight tetrahedra. These chains are further linked by isolated EuO8 square antiprisms, forming a three-dimensional framework. The K+ ions are located in pseudo-hexagonal channels running along [overline{2}01] and are surrounded by nine O atoms in a distorted environment.