Structure analysis of a Mn-doped willemite-type compound, H0.12(Zn1.89(3)Mn0.05(1)□0.06)Si1.00(1)O4

Large single crystals of a well-known green phosphor, Mn-doped willemite (alpha-Zn2SiO4)-type compound were grown from molten MnF2/Li2MoO4. In this structure Mn2+ and defects partially replace Zn2+ at two independent sites, and there are no cation species in the middle of six-membered ring channels. As a consequence of 3% defective sites (square), this structure may have protons for ensuring its electrostatic neutrality. Although the position of H+ could not be clearly found the present study indicates the presence of protons in the vicinity of oxygens to make relative short H...O bonds below 1.6 angstrom. Two unusual, broad IR bands about 1780 and 2360 cm(-1) can be explained by disordering of strongly bonded O...H groups. This compound represents a structural unit, H-0.12(Zn1.89(3)Mn0.05(1)square(0.06))Si1.00(1)O4, based on X-ray single crystal diffraction, electron microprobe, and FT-IR spectroscopy. (C) 2013 Elsevier Inc. All rights reserved.