Synthesis, characterization and magnetic investigation of (NH4) 0.5Mn1.25(H2O 2 [BP2O8].0.5H2O

Abstract

A new borophosphate compound with the composition (NH4) χ Mn((3-χ)/2)(H2O)2 [BP2O8]·(1-x)H2O was prepared under mild hydrothermal conditions and characterized by X-ray powder diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) methods. The title compound was synthesized from MnCl2 ·2H2O, H3BO3, and (NH4)2HPO4 with variable molar ratios by heating at 180 °C for 7 days in an autoclave. The X-ray diffraction data of the water insoluble polycrystalline powder was indexed using the TREOR program in hexagonal system with the unit cell parameters of a = 9.5104, c = 15.7108 Å, Z = 6 and the space group P65 (No.176). (NH4)χMn((3-χ)/2) (H2O)2 [BP2O8]·(1-x) H2O is isostructural with (NH4)χ MII((3-χ)/2)/(H2O)2 [BP2O8]·(1-x)H2O (MII = Co, Cd, Mg; x = 0.5-1). Its unit cell parameters and hkl values were in good agreement with the other isostructural compounds. This is the first report presenting both the synthetic details and the indexed X-ray powder diffraction pattern of this compound along with the characterization by FTIR, thermal gravimetric analysis, scanning electron microscopy and EPR. © Versita Warsaw and Springer-Verlag Berlin Heidelberg 2007.