Synthesis and structural study of phosphates K2Mg0.5Zr1.5(PO4)3, Rb2Mg0.5Zr1.5(PO4)3, and Cs2Mg0.5Zr1.5(PO4)3 with langbeinite structure

CsAlZr2(PO4)4: an anhydrous aluminium zirconium phosphate with a novel three-dimensional framework

“…Introduction of M IV (M = Ti, Zr, Ge, Sn) cations into the phosphates can result in many different threedimensional frameworks with the basic unit of MO 6 octahedra and PO 4 tetrahedra, such as KTiPO 5 (Tordjman et al, 1974) and NaZr 2 (PO 4 ) 3 (Hagman et al, 1968). For Zr IV cations, the reported phosphates include KZr 2 (PO 4 ) 3 (Sljukic et al, 1969), K 4 CeZr(PO 4 ) 4 (Ogorodnyk et al, 2006), Na 3 AZr(PO 4 ) 3 (A = Mg, Ni; Chakir et al, 2006), A 2 Mg 0.5 Zr 1.5 (PO 4 ) 3 (A = K, Rb, Cs; Orlova et al, 2005) and NaNbZr(PO 4 ) 3 (Bennouna et al, 1995), etc. We expected that the introduction of AlO 4 groups, which may serve as bridges between ZrO 6 and PO 4 building units, would result in new zirconium phosphate compounds with novel architectures.…”

Li(H2O)2-x[Zr2(PO4)3]: A Li-Filled Langbeinite Variant (x = 0) as a Precursor for a Metastable Dehydrated Phase (x = 2)

“…; X = S 6+ , P 5+ , Se 6+ , Mo 6+ , etc. ). − Langbeinite-type compounds have attracted much attention, because of their ferroelastic and ferroelectric properties, − as well as their structural phase transitions. − Recent studies have shown that, by incorporation of lanthanide ions into langbeinite-type phases, new applications may be envisaged, such as laser materials and nonlinear optical systems …”

Equilibrium langbeinite-related phosphates Cs1 + x Ln x Zr2 − x (PO4)3 (Ln = Sm–Lu) in the melted systems Cs2O–P2O5–LnF3–ZrF4

“…For sodium, Na 2 MTi(PO 4 ) 3 (M = Fe, Cr) were obtained and characterized by Isasi & Daidouh (2000), while the group of potassium-containing langbeinites is the largest: KTi 2 (PO 4 ) 3 (Masse et al, 1972), K 2 Ti 2 (PO 4 ) 3 (Leclaire et al, 1989), K 1 + x Ti 2 À y Al y (PO 4 ) 3 (Slobodyanik et al, 1991), K 2 CrTi(PO 4 ) 3 (Boudjada & Perret, 1977;Norberg, 2002), A 2 MTi(PO 4 ) 3 , A = K, Rb, Tl; M = Cr, Fe (Perret & Boudjada, 1979), K 2 VTi (PO 4 ) 3 (Rangan & Gopalakrishnan, 1994), K 2 MTi(PO 4 ) 3 , M = Er, Yb, Y (Norberg, 2002), K 2 M 0.5 Ti 1.5 (PO 4 ) 3 , M = Mn, Co, Ni Ogorodnyk et al, 2007), K 2 MZr(PO 4 ) 3 , M = Y, Gd (Wulff et al, 1992), K 2 FeZr(PO 4 ) 3 (Orlova et al, 2003), K 2 LnZr(PO 4 ) 3 , Ln = Ce-Lu (Trubach et al, 2004b), K 2 BiHf(PO 4 ) 3 (Losilla et al, 1998) (Lajmi et al, 2003). Rubidium-containing langbeinites are much more scarce: Rb 2 FeZr(PO 4 ) 3 (Trubach et al, 2004a), Rb 2 YbTi(PO 4 ) 3 and Rb 2 Yb 0.32 Ti 1.68 (PO 4 ) 3 (Gustafsson et al, 2005), Rb 2 Mg 0.5 Zr 1.5 (PO 4 ) 3 (Orlova et al, 2005), Rb 2 YTi(PO 4 ) 3 (Gustafsson et al, 2006). Cs 2 Mg 0.5 Zr 1.5 (PO 4 ) 3 (Orlova et al, 2005), however, is the only example with caesium cations in the cavities.…”

“…Rubidium-containing langbeinites are much more scarce: Rb 2 FeZr(PO 4 ) 3 (Trubach et al, 2004a), Rb 2 YbTi(PO 4 ) 3 and Rb 2 Yb 0.32 Ti 1.68 (PO 4 ) 3 (Gustafsson et al, 2005), Rb 2 Mg 0.5 Zr 1.5 (PO 4 ) 3 (Orlova et al, 2005), Rb 2 YTi(PO 4 ) 3 (Gustafsson et al, 2006). Cs 2 Mg 0.5 Zr 1.5 (PO 4 ) 3 (Orlova et al, 2005), however, is the only example with caesium cations in the cavities. Phosphates with the langbeinite structure containing only barium or only lead cations [Ba 1.5 V 2 (PO 4 ) 3 ; Droß & Glaum, 2004; Pb 1.5 V 2 (PO 4 ) 3 ; Shpanchenko et al, 2005] are also relatively rare.…”