Two potassium rare-earth polyphosphates KLn(PO3)4 (Ln=Ce, Eu): Structural, optical, and electronic properties

Spectroscopy and energy level location of the trivalent lanthanides in LiYP4O12

“…Note that the excitation intensity starts to drop steeply above 8.6 eV where the phosphate groups are being excited. Figure 5 shows the excitation and emission spectra [8], and in LiLaP 4 O 12 with the even larger La rare earth the CT band was reported to be located at 4.68 eV [1]. Similar observations as function of rare earth site size were reported for other families of related compounds [13,21].…”

“…in LiLaP 4 O 12 [1] and KEuP 4 O 12 [8]. Charge transfer luminescence was reported for Yb 3+ in LiYP 4 O 12 [9].…”

Synthesis and Structural Characterization of Yttrium Polyphosphates AY(PO3)4 (A = Rb, Tl, Cs) and Site‐selective Spectroscopy of Eu3+ Doped Samples

“…Because of its intermediate size between large and small alkaline cations, K + plays a special role in the long‐chain polyphosphates, being at the border line of the types II and IV. While most of the K Ln (PO 4 ) 3 long‐chain polyphosphates exhibit two polymorphs with type III and IV structures, KCe(PO 4 ) 3 presents two polymorphic forms with types II and III (monoclinic, P 2 1 ) 30,31. In the present context, the type III is not to be considered because it does not contain channels with double columns of alkaline cations.…”

KPr(PO3)4

“…All KLn(PO 3 ) 4 polyphosphates (Ln is a trivalent rare earth element) reported up to now adopt type III except for KYb(PO 3 ) 4 (Palkina et al, 1981). For corresponding isotypic crystal structures, see: Zhu et al (2009) for Ce and Eu; Horchani-Naifer et al (2008) for Y; Parreu et al (2006) for Gd and Nd;Xing et al (1987) for Tb; Ninghai et al (1984) for Eu; Lin et al (1983) for La; Krutik et al (1980) for Er;Hong et al (1975) for Nd. For a review of the crystal chemistry of phosphates, see: Durif (1995).…”