Synthesis and crystal structure of NZP-type thorium−zirconium phosphate

Microcrystals of Th1/4Zr2(PO4)3 were synthesized by thermal treatment (900 °C) of the material obtained using sol−gel technology (including organic complex formation and etherification). Their structure [hexagonal, P3̅c, a = b = 8.7311(4) Å, c = 23.309(2) Å] includes the three-dimensional [Zr2(PO4)3]− NASICON-type network and extraframework 6-fold-coordinated thorium(IV) cations.We express our thanks for financial support from the Spanish Ministerio de Educación y Ciencia (MAT2006-13548-C02-02, MAT2006-01997, and Factoría de Crystalización—Consolider Ingenio 2010) and the Gobierno del Principado de Asturias (PCTI 2006-2009). The authors are also grateful to the SpLine Beamline staff for support during the powder XRD experiments and to MEC and CSIC (Intramural 2004 5 OE 292) for financial support to carry out the synchrotron powder XRD experiments.Peer reviewe