Synthesis and visible-near-infrared photoluminescence emission of Er3+-doped LnP5O14 (Ln = La, Gd) ultraphosphates

Extended Condensed Ultraphosphate Frameworks with Monovalent Ions Combine Lithium Mobility with High Computed Electrochemical Stability

“…The degree of phosphate condensation decreases in the order Li 3 P 5 O 14 > Li 4 P 6 O 17 > LiPO 3 > Li 4 P 2 O 7 > Li 3 PO 4 . For Li 3 P 5 O 14 , where the P 20 O 56 12− anionic layers have the highest degree of condensation, the thermodynamic stability against oxidation is highest while the stability against reduction is poorest. Li 4 P 6 O 17 has the second highest degree of anionic condensation; hence, the stability against oxidation is second only to Li 3 P 5 O 14 and the stability against reduction is only higher than that of Li 3 P 5 O 14 .…”

“…The P 5 O 14 3− anion could adopt a different 2D layered arrangement with different sizes of rings based on alternating arrangement of internal and branching tetrahedra. The P 5 O 14 3− layers in monoclinic YP 5 O 14 present a combination of 20-and 8-membered rings, 15 while the P 10 O 28 6− layer in triclinic CeP 5 O 14 presents 12-membered corrugated rings, which have the same connectivity as the infinite P 20 O 56 12− layers in Li 3 P 5 O 14 , as shown in Figure 8. 94 These rings are interconnected with each other in 2D through their branching PO 4…”

“…Ultraphosphates have been shown to be attractive matrices for lasing materials due to their desirable optical properties, which are strongly dependent upon their unique crystal structural features. 10 − 12 Thus far, a series of divalent, trivalent, or mixed cation ultraphosphates were reported, such as MgP 4 O 11 , 13 YP 5 O 14 , 14 , 15 and Na 3 MP 8 O 23 (M = Fe, Al, Ga). 6 , 16 The structural chemistry of ultraphosphates is somewhat analogous to that of silicates and aluminates.…”

“…Ultraphosphates have been shown to be attractive matrices for lasing materials due to their desirable optical properties, which are strongly dependent upon their unique crystal structural features. − Thus far, a series of divalent, trivalent, or mixed cation ultraphosphates were reported, such as MgP 4 O 11 , YP 5 O 14 , , and Na 3 MP 8 O 23 (M = Fe, Al, Ga). , The structural chemistry of ultraphosphates is somewhat analogous to that of silicates and aluminates. Crystal structures with 2,3-connected anionic networks occur in polysilicates, phyllosilicates, and polyaluminates, such as loop-branched single chain Si 4 O 11 4– in Li 2 Mg 2 Si 4 O 11 , double chain Al 3 O 8 7– in Na 7 Al 3 O 8 , , and infinite single layer Si 3 O 8 4– in Na 2 ZnSi 3 O 8 (Figure e) .…”