Cobalt borate phosphate, Co-3[BPO7], synthesis and characterization

Single crystals of Co-3[BPO7],I were obtained by boron flux method and char acterized by single-crystal diffraction data. The compound crystallizes in the monoclinic space group Cm with 9.774(2), b = 12.688(2), c = 4.9057(8) A ngstrom, beta = 119.749(2)degrees; V= 528.20(15) Angstrom (3); Z = 4. The s tructure consists of Co in trigonal bipyramids, square pyramids, and distor ted octahedra. Polyhedral Co centers, triangular B centers, and tetrahedral P centers are joined together to form a three-dimensional network. The tem perature dependence of the magnetic susceptibility of the compound follows the Curie-Weiss law to 30 K. Below this temperature, the magnetic behavior displayed first antiferromagnetic ordering followed by ferrimagnetic coupli ng at 25 K. (C) 2001 Academic Press.