LiTb(PO₃)₄

Abstract

The lithium terbium polyphosphate LiTb(PO3)4 was prepared by the flux method using a large excess of H3PO4. It was structurally characterized by single‐crystal X‐ray diffraction and found to be isotypic with LiYb(PO3)4. The basic structural units are endless spiral chains, (PO3)n, along the b‐axis direction. The Li+ and Tb3+ cations alternate on twofold axes and are four‐ and eight‐coordinated, respectively. The results of an optical study of this material are also given and discussed.

LiDy(PO3)4

“…The polyphosphate chains display two type of distances, P-O terminal ranging from 1.475 (5) to 1.500 (5)Å and P-O bridging, noticeably longer, ranging from 1.573 (5) to 1.619 (5) Å. These distances are comparable with those reported for other condensed phosphates (Durif, 1995;Averbuch-Pouchot & Bagieu Beucher, 1987;Chehimi-Moumen & Férid, 2007;Férid, 2006, Ben Zarkouna et al, 2007.…”

“…Er (Liu et al, 1983, Ben Zarkouna et al, 2005,Yb (Ben Zarkouna et al, 2004), Gd (Ettis et al, 2006), Tb (Ben Zarkouna et al, 2007), showed that all these compounds crystallize in space group C2/c and have similar unit-cell parameters.…”

The type IV polymorph of KDy(PO3)4

“…The P-O distances within the polyphosphate chains range from 1.476 (3) to 1.492 (3) Å for the terminal P-O bonds and from 1.588 (3) to 1.608 Å for the bridging P-O bonds (Table 1 and Fig. 2) and are comparable with those of other condensed phosphates (Durif, 1995;Averbuch-Pouchot & Bagieu-Beucher, 1987;Chehimi-Moumen & Fé rid, 2007;Fé rid, 2006;Ben Zarkouna et al, 2007).…”

Lithium samarium polyphosphate, LiSm(PO3)4

“…The compound LiSm(PO 3 ) 4 has been reported but only unit cell parameters have been refined from powder X-ray diffraction data (Ferid et al, 1984). The single-crystal structure determination performed here confirms that it is isotypic with LiLn(PO 3 ) 4 (Ln = Y, La, Nd, Eu, Gd, Tb, Dy, Er, Yb) (Ben Zarkouna et al, 2007). The structure features two P sites ( Fig.…”