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Abstract: The interaction of TiN with Na2O–K2O–P2O5 melts was investigated at (Na+K)/P molar ratios of 0.9, 1.0, and 1.2 and at Na/K molar ratios of 1.0 and 2.0. Interactions in the system led to the loss of nitrogen and the partial loss of phosphorus and resulted in the formation of KTiP2O7 and langbeinite‐type K2−xNaxTi2(PO4)3 (x=0.22–0.26) solid solutions over the temperature range of 1173 to 1053 K. The phase compositions of the obtained samples were determined by using X‐ray diffraction (including Rietveld refinement), scanning electron microscopy (using energy‐dispersive X‐ray spectroscopy and element mapping), FTIR spectroscopy, and thermogravimetric analysis/differential thermal analysis. K1.75Na0.25Ti2(PO4)3 was characterized by single‐crystal X‐ray diffraction [P213 space group, a=9.851(5) Å]. The 3D framework is built up by TiO6 octahedra and PO4 tetrahedra sharing all the oxygen vertices with the formation of cavities occupied by K(Na) cations. Only one of the two crystallographically inequivalent potassium sites is partially substituted by sodium, and this was confirmed by calculating the bond‐valence sum. The thermodynamic stability of K1.75Na0.25Ti2(PO4)3 crystals and the preferable occupation sites of NaK cationic substitutions were investigated by DFT‐based electronic structure calculations performed by the plane‐wave pseudopotential method. [ABSTRACT FROM AUTHOR]

Solid solutions KTi1-XHfXOPO4 (х = 0.008 - 0.107) possessing the KTiOPO4 structure, have been synthesized in molten system K2O-P2O5-TiO2-HfF4. The crystal growth experiment of Hf-doped KTP crystal has been reported. The X-ray powder diffraction data and chemical analysis are also presented. It has been shown that KTiOPO4 crystal structure slightly changes when Hf incorporates into the framework. Transmission/absorption spectra of KTi0.974Hf0.026OPO4 crystals have been recorded. The incorporation of Hf ions shifts the optical absorption edge in the UV-visible spectrum towards the long-wavelength region with absorption near 387 nm. [ABSTRACT FROM AUTHOR]

The solid solution KNi0.93FeII0.07FeIII(PO4)2 {potassium [nickel(II)/iron(II)] iron(III) bis(orthophosphate)} has been prepared by the flux method. The compound shows a new type of structure for a phosphate with the general composition MI MII MIII(PO4)2. The framework is formed by [(Ni/Fe)O6] polyhedra [Fe site occupancy = 0.069 (14)] linked via shared oxygen vertices forming a cis-like parallel chain stretching along a and [FeO5] polyhedra (located on alternate sides of the chains) connected via two types of PO4 groups into a three-dimensional structure. The K atoms are disordered between two sites, denoted K1 A and K1 B, with occupancies of 0.930 (9) and 0.070 (9), respectively, and reside inside channels along the a axis. Calculations of the Voronoi-Dirichlet polyhedra of the K atoms give a coordination scheme for K1 A of [9 + 3] and for K1 B of [10 + 2]. The most remarkable feature of the structure is the splitting of the K-atom site and the population of the K1 A and K1 B positions due to substitution of Ni by Fe in the (Ni/Fe) position. [ABSTRACT FROM AUTHOR]

Crystals of dipotassium iron(III) tin(IV) tris(orthophosphate) were grown from a self-flux in the system K2O-P2O5-Fe2O3-SnO2. The title compound is isotypic with the mineral langbeinite, K2Mg2(SO4)3. Its three-dimensional [M2(PO4)3]∞ framework is composed of [MO6] (M = Sn, Fe) octahedra and [PO4] tetrahedra interlinked via vertices. In comparison with the previous refinement from X-ray powder data [Aatiq, Haggouch, Bakri, Lakhdar & Saadoune. (2006). Powder Diffr. 21, 214-219], the present reinvestigation from single-crystal data allows a more precise determination of the distribution of the Fe and Sn atoms over two crystallographic positions and a revision of the P-O and M-O [M = K, (Fe, Sn)] bond lengths. For the two K+ cations, two different polyhedra with coordination numbers of 9 and 12 are observed. The (Fe, Sn) and K atoms are located on three-fold axes. [ABSTRACT FROM AUTHOR]

Tetra­potassium cerium(IV) zirconium tetra­kis­(mono­phos­phate) crystallizes in the tetra­gonal system (space group I41/ amd). A complex disorder in K4CeZr(PO4)4 involves the mixing of Ce and Zr atoms on a single site with m2 symmetry and the splitting of P- and O-atom positions, equivalent to a rotation of the phosphate groups, to yield eight- and sixfold coordination environments around Ce and Zr, respectively. The K atoms are located in tunnels running parallel to the a and b axes. [ABSTRACT FROM AUTHOR]

Crystals of the title compound, CsCd(P3O9), were grown from a melt. The structure is isotypic with CsCdP3O9. The three-dimensional framework is built up from [CaO6] octa­hedra linked together via corner-sharing to cyclic [P3O9]3− anions. The Cs cations are situated in large cavities in the [CaP3O9]∞− anion framework. Except for one P and three O atoms, all other atoms (one Cs, one Ca, one P and three O atoms) are located on mirror planes. [ABSTRACT FROM AUTHOR]

Aliovalent KTP isomorphic compounds potassium chromium niobium oxide phosphate, KCr0.5Nb0.5OPO4, and potassium iron niobium oxide phosphate, KFe0.5Nb0.5OPO4, exhibit structures that differ from that of the non-centrosymmetric KTiOPO4. There are two crystallographically independent octa­hedral sites, M1 and M2, statistically occupied by Nb and Cr (or Fe) atoms. The M1O6 and M2O6 octa­hedra are connected alternately to form a chain with a cis– trans arrangement. The Nb atoms prefer the M2 sites arranged in a cis-like configuration. Each PO4 tetra­hedon has the P atom on a twofold axis. Site-splitting at the K-atom position is observed in both compounds. In the isomorphous structures, one Nb atom lies on an inversion centre and the other on a twofold axis. Similarly with the pairs of Fe/Cr sites, one is on an inversion centre and the other on a twofold axis. [ABSTRACT FROM AUTHOR]

Dipotassium bismuth phosphate tungstate has been synthesized using the flux technique. It crystallizes in the space group Ibca and is isotypic with Na2Y(PO4)(MoO4). It exhibits a layered structure, which is built up from [Bi(PO4)(WO4)]∞2- layers. Each layer is composed of [BiO8]∞ zigzag chains, which are connected via PO4 and WO4 tetrahedra. The parallel anionic [Bi(PO4)(WO4)]∞2- layers are stacked along [100] and are held together by K+ counter-cations which occupy sites in the interlayer space. Bi, W and P atoms are all located on twofold axes. [ABSTRACT FROM AUTHOR]

During multivalent ions insertion processes, intense electrostatic interaction between charge carriers and host makes the high‐performance reversible Al3+ storage remains an elusive target. On account of the strong electrostatic repulsion and poor robustness, Prussian Blue analogues (PBAs) suffer severely from the inevitable and large strain and phase change during reversible Al3+ insertion. Herein, we demonstrate an entropy‐driven strategy to realize ultralong life aqueous Al‐ion batteries (AIBs) based on medium entropy PBAs (ME‐PBAs) host. By multiple redox active centers introduction, the intrinsic poor conductivity can be enhanced simultaneously, resulting in outstanding capabilities of electrochemical Al3+ storage. Meanwhile, the co‐occupation at metal sites in PBA frameworks can also increase the M−N bond intensity, which is beneficial for constraining the phase change during consecutive Al3+ reversible insertion, to realize an extended lifespan over 10,000 cycles. Based on the calculation at different operation states, the fluctuation of ME‐PBA lattice parameters is only 1.2 %. Assembled with MoO3 anodes, the full cells can also deliver outstanding electrochemical properties. The findings highlight that, the entropy regulation strategy could uncover the isochronous constraint on both strain and phase transition for long‐term reversible Al3+ storage, providing a promising design for advanced electrode materials for aqueous multivalent ions batteries. [ABSTRACT FROM AUTHOR]

During multivalent ions insertion processes, intense electrostatic interaction between charge carriers and host makes the high‐performance reversible Al3+ storage remains an elusive target. On account of the strong electrostatic repulsion and poor robustness, Prussian Blue analogues (PBAs) suffer severely from the inevitable and large strain and phase change during reversible Al3+ insertion. Herein, we demonstrate an entropy‐driven strategy to realize ultralong life aqueous Al‐ion batteries (AIBs) based on medium entropy PBAs (ME‐PBAs) host. By multiple redox active centers introduction, the intrinsic poor conductivity can be enhanced simultaneously, resulting in outstanding capabilities of electrochemical Al3+ storage. Meanwhile, the co‐occupation at metal sites in PBA frameworks can also increase the M−N bond intensity, which is beneficial for constraining the phase change during consecutive Al3+ reversible insertion, to realize an extended lifespan over 10,000 cycles. Based on the calculation at different operation states, the fluctuation of ME‐PBA lattice parameters is only 1.2 %. Assembled with MoO3 anodes, the full cells can also deliver outstanding electrochemical properties. The findings highlight that, the entropy regulation strategy could uncover the isochronous constraint on both strain and phase transition for long‐term reversible Al3+ storage, providing a promising design for advanced electrode materials for aqueous multivalent ions batteries. [ABSTRACT FROM AUTHOR]

The title compound is prepared from KPO3 and NiO (Pt crucible, 1173 K) as a self-flux to which K2ZrF6 is added. [ABSTRACT FROM AUTHOR]

Polycrystalline AgCa10(PO4)7 is obtained by solid state reaction of a stoichiometric mixture of Ag3PO4, CaCO3, and CaHPO4 (porcelain crucible, calcination at 873 K, annealing at 1173 K, 20 h). [ABSTRACT FROM AUTHOR]

Aliovalent K0.92In0.46Nb0.54OPO4 (KINP, potassium indium niobium oxide phosphate) features a chain structure involving corner-sharing [ MO6] octahedra ( M = In/Nb), which allows this compound to be recognized as a member of the KTiOPO4 (KTP) family. However, its crystallization in the polar space group P41 belonging to the 4/ m Laue group generates its own subclass of KTP-related compounds. The unit cell contains 18 symmetry-independent atoms occupying general positions. The cis– cis principle of octahedral arrangement is observed for each of the separate [ MO6]∞ chains. The observed variations in the cis– cis linkage are critically important for nonlinear optical properties and distinguish the present compound from other KTP-related structures. The anionic framework adopts one-dimensional tunnels running orthogonal to the ab plane. The K+ ions are arranged in the [001] direction at a distance of c. Merohedral twinning was detected during the structure refinement. [ABSTRACT FROM AUTHOR]

Nonacalcium chromium(III) heptakis(orthophosphate) has been obtained from a melt in the system Cs2O–CaO–Cr2O3 using a polyphosphate flux. The three-dimensional framework is related to the whitlockite structure [β-Ca3(PO4)3] and is built up from CaO8 and CaO9 polyhedra sharing vertices, edges and faces, further connected by PO4 tetrahedra and CrO6 octahedra. The Cr, one P and one O atom are located on threefold rotation axes. Ca9Cr(PO4)7 is isotypic with Ca9Fe(PO4)7. The crystal studied was an inversion twin. [ABSTRACT FROM AUTHOR]

The title compound, tris­odium titanium nitride tris­(phos­phate), is built up from TiIIIO6 octa­hedra linked together via [N(PO3)3] groups, the latter arising from three PO3N tetra­hedra sharing an N vertex. Three sodium cations complete the structure, which is also found for Na3AlN(PO3)3. All the metal cations and the N atom occupy special positions with site symmetry 3. [ABSTRACT FROM AUTHOR]

The particularities of the chemical interaction in systems MIPO3 -MIIO(or Mn2O3)- MICl ( MI - Na, K; MII - Mg, Co, Ni, Zn) have been investigated at the temperature 1073 K and molar ratios P/ Mx = 1 or 2 and MICl/( MIPO3 + MIIO(or Mn2O3)) = 30. The conditions of formation of complex phosphates MІMIIPO4 and Na4Ni3(PO4)2P2O7 have been found. Influences of the nature of alkali and bivalent metals on the products composition were discussed. The advantages of chloride melts using (synthesis time reduction and temperature reducing) for preparing of complex phosphates were shown. The synthesized compounds have been characterized using the powder X-ray diffraction, Fourier transform infrared and diffuse reflectance spectroscopies. [ABSTRACT FROM AUTHOR]

Nine novel phosphates, based upon a combination of caesium, zirconium and lanthanide ions, were obtained from fluoride-containing fluxes using high-temperature crystallization. The structures of Cs1.80Eu0.80Zr1.20(PO4)3 (CsEuZrP), Cs1.79Gd0.79Zr1.21(PO4)3 (CsGdZrP), Cs1.87Tb0.87Zr1.13(PO4)3 (CsTbZrP), Cs1.67Dy0.67Zr1.33(PO4)3 (CsDyZrP), Cs1.75Ho0.75Zr1.25(PO4)3 (CsHoZrP), Cs1.78Er0.78Zr1.22(PO4)3 (CsErZrP), Cs1.70Tm0.70Zr1.30(PO4)3 (CsTmZrP), Cs1.52Yb0.52Zr1.48(PO4)3 (CsYbZrP) and Cs1.63Lu0.63Zr1.37(PO4)3 (CsLuZrP) were solved using single-crystal X-ray diffraction. All compounds are isostructural to the mineral langbeinite (cubic system, space group P213). Their framework structures originate from the cross-linking of metal octahedra [ MO6] ( M = Zr, Ln) by phosphate tetrahedra. Cs+ cations are located in the closed cavities of the framework and preferentially occupy one of the two available sites. The principles of crystallization of the equilibrium langbeinite-related phosphates in the fluxes of the system Cs2O–P2O5–LnF3–ZrF4 (Ln = La–Nd, Sm–Lu) are discussed based on their crystal structures. [ABSTRACT FROM AUTHOR]

The article discusses the intermolecular structure of Bis{1-methyl-5-[3-(1-methyl-1H-tetrazolo[5,1-a]-isoindol-5-yI)allylidene]-5H-tetrazolo[5,1 -a]iso-indol-1 -ium} tetracyanonickelate(II). The molecular structure consists of two organic cations, C21H17N8+ or [MTIT]+, and a centrosymmetric inorganic dianion, [Ni(CN)4]2-. The ions stack along the b axis and are connected by a number of C-H...N hydrogen bonds. These cations are positioned axial to the Ni atoms. One more pair of N...H contacts is formed with two dye cations that are almost perpendicular to the plane of the [Ni(CN)4]2-.

Two simple pathways using metallic copper or copper salts are proposed for the synthesis of hybrid compounds under mild conditions. A variety of Strandberg- and mixed-metal Keggin-based products, namely, (NH4)5 n{[Cu(en)2][PMo8V4O40]} n ·9 nH2O ( 1), (NH4)4 n{[Cu(en)(H2O)][P2Mo5O23]} n ·3.5 nH2O ( 2), (NH4)7[PMo8V4O40] ·17H2O ( 3) and (NH4)2 n{[Cu(en)2][Cu(en)(H2O)][P2Mo5O23]} n ·3 nH2O ( 4), were isolated upon the variation of the composition of the reaction system. A rare four-substituted [PMo8V4O40]7- Keggin anion was obtained. The influence of the vanadium source [V2O5, NH4VO3 or (NH4)2V6O16] and the copper precursor (copper powder vs. copper salts) on the nature of the resulting products was studied. An ex situ electron paramagnetic resonance (EPR) spectroscopy study revealed the formation of VIV and CuII centres in the reaction mixture during Cu0 dissolution. The obtained compounds possess electrocatalytic activity in the reduction of iodate and nitrite anions, and a carbon-paste electrode modified with 4 exhibited a linear current response to l-cysteine. Furthermore, 4 demonstrated rapid and almost complete adsorption of a cationic dye. [ABSTRACT FROM AUTHOR]

Interactions in the systems MIPO3-MIIO (or Mn2O3)-MICl (MI: Na, K; MII: Mg, Co, Ni, Zn) are investigated at molar ratios P/Mx = 1 or 2, and MICl/(MIPO3 + MIIO) = 30 (porcelain crucibles, 1073 K, 3-5 h). [ABSTRACT FROM AUTHOR]

A very broad vibrational band ranging from 1000 up to 4000 cm−1 and two relatively sharp bands at 5000 and 5027 cm−1 are found in the Raman scattering spectrum of hydroxyapatite-containing films obtained by gas detonation spray method. We developed a theoretical model that interprets the broad band as a result of strong interaction between the high-frequency hydrogen bond vibrations and lattice phonons. Both sharp bands around 5000 cm−1 are assigned to the overtones of v-OH vibrations. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The interaction in the molten system Rb2O-P2O5-TiO2-NiO was investigated at different molar ratios Rb/P = 0.5-1.3, fixed Ti/P = 0.15, Ti/Ni = 1.0 at temperature range 1073-953 K. The conditions of formation of complex phosphates RbTi2(PO4)3, Rb2Ni0.5Ti1.5(PO4)3 and RbNiPO4 have been determined. The new phosphate Rb2Ni0.5Ti1.5(PO4)3 (space group P213, a = 9.9386(2) Å) has been obtained and investigated by the single crystal X-ray diffraction and FTIR-spectroscopy. It has langbeinite-like structure, that is built up from mixed (Ni/Ti)O6-octahedra and РО4-tetrahedra. Rubidium atoms are located in closed cavities of 3D-framework. [ABSTRACT FROM AUTHOR]

The formation of complex phosphates is investigated in melts containing Rb2CO3, H3PO4, TiO2, and NiO at different molar ratios of Rb:P = 0.5-1.3, Ti:P = 0.15, Ti:Ni = 1.0 at 1073-953 K (Pt crucible, 1273 K, 3 h). [ABSTRACT FROM AUTHOR]