From reaction of excess lithium with tin, we isolate well-crystallized LiSn and solve the crystal structure from single-crystal X-ray diffraction data. The orthorhombic structure (space group ) features the same coordination polyhedra around tin and lithium as previously predicted by electronic structure calculations for this composition, however differently arranged. An extensive analysis, including thermodynamic integration using Langevin dynamics in combination with a machine-learning potential (moment tensor potential), is conducted to understand the thermodynamic stability of this LiSn structure observed in our experiments.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
March 2021
The first nitridogermanates(III) Ca [Ge N ] and Sr [Ge N ] were synthesized from sodium flux and structurally characterized by powder and single crystal X-ray diffraction, respectively. They crystallize isostructurally to each other and homeotypic to Ca [Cr N ]H in space group R . They feature unprecedented, mutually isolated, ethane-like [Ge N ] anions in a staggered conformation.
View Article and Find Full Text PDFMaterials (Basel)
February 2020
Single crystals of aluminum substituted strontium hexaferrite SrFeAlO were grown from sodium oxide based flux. The substitution level aimed for was = 1.2.
View Article and Find Full Text PDFSolutions of gallium trihalides GaX (X=F, Cl, Br, I) and their ammoniates in liquid ammonia were studied at ambient temperature under autogenous pressure by multinuclear ( Ga, Cl, Br) NMR spectroscopy. To unravel the role of pH, the analyses were done both in absence and in presence of ammonium halides, which are employed as mineralizers during ammonoacidic gallium nitride crystal growth. While gallium trifluoride and its ammoniate were found to be too sparingly soluble to give rise to a NMR signal, the spectra of solutions of the heavier halides reveal the presence of a single gallium-containing species in all cases.
View Article and Find Full Text PDFThe first quasi-binary acetonitriletriide Sr [C N] has been synthesised and characterised. The nearly colourless crystals were obtained from the reaction of Sr metal, graphite, and elemental N , generated by decomposition of Sr(N ) , in a sealed Ni ampoule with the aid of an alkali metal flux. The structure of this compound was analysed via single-crystal X-ray diffraction and the identity of the [C N] anion was confirmed by Raman spectroscopy and further investigated by quantum-chemical methods.
View Article and Find Full Text PDFThe iron manganese nitride FeMnN was obtained by high-pressure-high-temperature synthesis from -FeN and elemental Mn at 15(2) GPa and 1573(200) K. The phase crystallizes isostructural to binary -FeN. In comparison to the corresponding binary iron nitride, the microhardness of -FeMnN is reduced to 6.
View Article and Find Full Text PDFBarium hexaferrite powder samples with grains in the μm-range were obtained from solid-state sintering, and crystals with sizes up to 5 mm grown from PbO, Na₂CO₃, and BaB₂O₄ fluxes, respectively. Carbonate and borate fluxes provide the largest and structurally best crystals at significantly lower growth temperatures of 1533 K compared to flux-free synthesis (1623 K). The maximum synthesis temperature can be further reduced by the application of PbO-containing fluxes (down to 1223 K upon use of 80 at % PbO), however, Pb-substituted crystals BaPbFeO with Pb contents in the range of 0.
View Article and Find Full Text PDFA new complex ternary amide, Rb [Mn(NH ) ], which simultaneously contains both transition and alkali metal catalytic sites, is developed. This is in line with the recently reported TM-LiH composite catalysts, which have been shown to effectively break the scaling relations and achieve ammonia synthesis under mild conditions. Rb [Mn(NH ) ] can be facilely synthesized by mechanochemical reaction at room temperature.
View Article and Find Full Text PDFThe combination of laser-heated diamond anvil cells and synchrotron Mössbauer source spectroscopy were used to investigate high-temperature high-pressure chemical reactions of iron and iron nitride Fe N with nitrogen. At pressures between 10 and 45 GPa, significant magnetic hyperfine splitting indicated compound formation after annealing at 1300 K. Subsequent in situ X-ray diffraction reveals a new modification of FeN with NiAs-type crystal structure, as also rationalized by first-principles total-energy and chemical-bonding studies.
View Article and Find Full Text PDFThe coexistence of three valence states of Mn ions, namely, +2, +3, and +4, in substituted magnetoplumbite-type BaFeMnO was observed by soft X-ray absorption spectroscopy at the Mn-L edge. We infer that the occurrence of multiple valence states of Mn situated in the pristine purely iron(III) compound BaFeO is made possible by the fact that the charge disproportionation of Mn into Mn and Mn requires less energy than that of Fe into Fe and Fe, related to the smaller effective Coulomb interaction of Mn (d) compared to Fe (d). The different chemical environments determine the location of the differently charged ions: with Mn occupying positions with (distorted) octahedral local symmetry, Mn ions prefer octahedrally coordinated sites in order to optimize their covalent bonding.
View Article and Find Full Text PDFK2[Mn(NH2)4] and K2[Zn(NH2)4] were successfully synthesized via a mechanochemical method. The mixture of K2[Mn(NH2)4] and LiH showed excellent rehydrogenation properties. In fact, after dehydrogenation K2[Mn(NH2)4]-8LiH fully rehydrogenates within 60 seconds at ca.
View Article and Find Full Text PDFSingle crystals of ZnF2(NH3)3 and ZnF2(NH3)2 were obtained under ammonothermal conditions (250 °C, 196 MPa and 500 °C, 136 MPa). Upon thermal decomposition of both ZnF2(NH3)3 and ZnF2(NH3)2, a microcrystalline powder of ZnF2(NH3) was obtained. ZnF2(NH3)3 and ZnF2(NH3)2 represent probable intermediates in a conceivable ammonothermal synthesis of the semiconductor Zn3N2 and manifest a rare trigonal-bipyramidal coordination of F(-) and NH3 ligands around Zn(2+) according to single-crystal X-ray diffraction.
View Article and Find Full Text PDFThe alkali metal amidozincates Li4 [Zn(NH2)4](NH2)2 and K2[Zn(NH2)4] were, to the best of our knowledge, studied for the first time as hydrogen storage media. Compared with the LiNH2-2 LiH system, both Li4 [Zn(NH2)4](NH2)2-12 LiH and K2[Zn(NH2)4]-8 LiH systems showed improved rehydrogenation performance, especially K2[Zn(NH2)4]-8 LiH, which can be fully hydrogenated within 30 s at approximately 230 °C. The absorption properties are stable upon cycling.
View Article and Find Full Text PDFOur attempts to synthesize the hitherto unknown binary copper(I) fluoride have led to first successes and a serendipitious result: By conproportionation of elemental copper and copper(II) fluoride in anhydrous liquid ammonia, two copper(I) fluorides were obtained as simple NH3 complexes. One of them presents an example of ligand-unsupported "cuprophilic" interactions in an infinite [Cu2 (NH3 )4 ](2+) chain with alternating Cu-Cu distances. We discovered that both copper(I) fluorides can easily be converted into Cu3 N at room temperature, just by applying a vacuum.
View Article and Find Full Text PDFA representative of the fluoride-containing iron pnictide high-temperature superconductors, namely CaFFeAs, was doped with sodium up to the composition CaNaFFeAs for the first time. Single crystals with an edge length in the range of 0.1 - 2.
View Article and Find Full Text PDFSingle crystals of garnet-type trimanganese(II) dichrom-i-um(III) tris-[orthogermanate(IV)], Mn(II) (3)Cr(III) (2)(GeO(4))(3), were obtained by utilizing a chemical transport reaction. Corres-ponding to the mineral garnet with the general formula A(II) (3)B(III) (2)(SiO(4))(3), each of the four elements occupies only one crystallographically distinct position. Mn(2+) occupies the respective A position (Wyckoff site 24c, site symmetry 2.
View Article and Find Full Text PDFSingle crystals of HfAs(1.7)Se(0.2) are grown by chemical transport reaction and their chemical composition characterized in detail by various analytical methods.
View Article and Find Full Text PDFInorg Chem
February 2007
The first representatives of 4H (BaMnO3-type structure, P63/mmc, Z = 4) and 9R (BaMnO3-type structure, Rm, Z = 9) inverse Perovskite phases are presented. The phases are obtained within the solid solutions (Sr3-xBaxN)E with E = Bi, Sb. The crystal structures and homogeneity ranges were studied by combined X-ray and neutron diffraction as well as chemical analyses.
View Article and Find Full Text PDFLi(3)[ScN(2)] was prepared from Li(3)N with Sc or ScN in a nitrogen atmosphere at 1020 K as a light yellow powder with an optical band gap of about 2.9 eV. The crystal structure was refined based on X-ray and neutron powder diffraction data (Ia$\bar 3$, Z=16, X-ray diffraction: R(profile)=0.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
May 2002