Features of the atomic and electronic structure of the new nonlinear optical crystal KAlFPO4

AVPO4F (A = Li, K): A 4 V Cathode Material for High-Power Rechargeable Batteries

“…To address these issues, we propose a replacement of V 4+ by V 3+ with a simultaneous substitution of O 2– by F – to preserve the electroneutrality, which results in a KVPO 4 F formula. It should be noted that KTP-type KMPO 4 F (M = Al, Cr, Fe) − counterparts are known; however, they have never been considered as electrode materials for rechargeable batteries. Here we report on a novel vanadium-based cathode material AVPO 4 F (A = Li, K) adopting a KTP-type framework for high power rechargeable batteries with enhanced specific energy and excellent rate capability.…”

Complex phosphates containing mono- and trivalent cations

“…100 Fluoride phosphates with different compositions can be obtained in the multicomponent M I F ± M III 2 O 3 ± H 3 PO 4 ± H 2 O systems (M I = Li, Na, K, NH 4 ; M III = Al, Fe, Ga, In, Y, Ho, Er) under the hydrothermal conditions. 83,85,86,101,102 For example, LiFe[(OH),F]PO 4 (synthetic mineral tavorite) 83 and analogues of natural iron phosphates, such as triphylite LiFePO 4 , sarcopside Fe 3 (PO 4 ) 2 and zwieselite Fe 2 FPO 4 , 102 After the successful synthesis of a series of porous crystalline aluminosilicates (zeolites) and aluminophosphates, attempts were made to prepare porous fluoride phosphates of the general formula A a M III x F y (PO 4 ) z (M III = Ga, Fe, In; A is organic amine). It was expected that these compounds would find use as catalysts, molecular sieves or ion exchangers.…”

“…Potassium-containing fluoride phosphates KM III FPO 4 are known for M III = Al, Cr, Fe, In. In the crystal structure of KAlFPO 4 , 101,112 the aluminium atoms are located in the [AlO 4 F 2 ] octahedra of two types, which differ in the positions of the F atoms (trans and cis). The structure of KInFPO 4 , unlike KAlFPO 4 , contains octahedra of only one type with a cis arrangement of the F atoms.…”

“…The PO 4 tetrahedra and M III O 6 octahedra are the main structural elements of tavorite and amblygonite. These polyhedra are linked in chains along the [101] direction through the common (OH, F) vertices. These chains are linked in a three-dimensional framework through the PO 4 tetrahedra (Fig.…”

Pushing KTiOPO4-like Nonlinear Optical Sulfates into the Deep-Ultraviolet Spectral Region

“…However, due to the TiO 6 octahedra in its crystal structure, its transparency window is merely down to 350 nm (corresponding to an energy bandgap of 3.52 eV), which limits the application of KTP in the short-wave spectral region. In the past several decades, a number of KTP-like phosphates, such as NH 4 TiOPO 4 , TlTiOPO 4 , AgTiOPO 4 , KAlFPO 4 , KGaFPO 4 , KGeOPO 4 , KVOPO 4 , and KMg­(H 2 O)­PO 4 have been discovered. This indicates that the KTP structure is so thermodynamically stable that it affords a large structural tolerance for various derivatives.…”