Orthorhombic Polymorph of ErP₅O₁₄, Crystal Structure and Characterization

Abstract

4 -507Orthorhombic Polymorph of ErPSO,,, Crystal Structure and Characterization Erbium pentaphosphate crystals have been characterized and the structure of the orthorhombic polymorph (type 111) determined by X-rays. It has been found that the orthorhombic samples of ErP,O,,, space group Pnma, crystallize mainly at higher temperatures and usually are much larger than monoclinic crystals, space group C2/c, obtained from lower-temperature crystallizations. Differences in fluorescence and upconversion properties between orthorhombic and monoclinic polymorphs have been detected.

Crystal Structures and Magnetic Properties of Rare-Earth Ultraphosphates, RP5O14 (R=La, Nd, Sm, Eu, Gd)

“…These structures are an addition to the partially established series of rare-earth ultraphosphate crystal structures that has been reported previously: 10,11), and YbP O (12). A structural determination of GdP O has also been reported (13), although the poor statistics obtained (e.g., R"0.103) and the use of block re"nement merited the full redetermination presented herein.…”

DyP5O14

“…Other structure refinements have been reported for LaP 5 O 14 (Cole et al, 2000), PrP 5 O 14 (Liu et al, 1991), NdP 5 O 14 (Albrand et al, 1974;Cole et al, 2000), SmP 5 O 14 (Cole et al, 2000), EuP 5 O 14 (Parrot et al, 1975;Cole et al, 2000), GdP 5 O 14 (Lin et al, 1983;Cole et al, 2000), TbP 5 O 14 (Lin et al, 1982), ErP 5 O 14 (Jeżowska-Trzebiatowska et al, 1980;Katrusiak & Kaczmarek, 1995), TmP 5 O 14 (Kangjing et al, 1982) and YbP 5 O 14 (Hong & Pierce, 1974).…”

An orthorhombic polymorph of the ultraphosphate YP5O14

“…Besides crystals of the title compound, crystals of the monoclinic polymorph were also obtained (Mbarek et al, 2009). For isotypic structures, see: Durif (1972) for the Ho member; Katrusiak & Kaczmarek (1995) and Dimitrova et al (2004) for the Er member. For a review of the crystal chemistry of ultraphosphates, see: Durif (1995).…”