Solubility of GaN in supercritical ammonia with ammonium chloride as a mineralizer

The solubility of GaN in supercritical ammonia with ammonium chloride as a mineralizer was measured with a weight-loss method. Temperature-, pressure-, and mineralizer concentration-dependence of the solubility of GaN were investigated. The solubility increased with increase in temperature, and its pressure dependence was very low. The solubility behavior was quite different from the case of using the mineralizer KNH₂ as a basic mineralizer.     

The Crystal Structure of InGaO3(ZnO)4: A Single Crystal X‐ray and Electron Diffraction Study

The crystal structure of the mixed oxide InGaO₃(ZnO)₄ has been determined from electron diffraction and single‐crystal X‐ray diffraction data. The compound crystallises in a hexagonal space group (P6₃/mmc; No. 194), deduced from convergent beam electron diffraction (CBED). Single crystals of InGaO₃(ZnO)₄ were grown from a K₂MoO₄ flux in sealed platinum tubes. Single crystal structure refinement from XRD data [a = 3.2850(2) Å; c = 32.906(3) Å; Z = 2; 4232 data, R₁ = 0.0685] reveals a compound with oxygen anions forming a closest‐packed arrangement. Within this packing In³⁺ cations occupy octahedral interstices, forming layers of edge sharing octahedra. In between these layers are regions with composition [Zn₄GaO₅]⁺ forming a wurtzite type of structure. Inversions of the ZnO₄ tetrahedra occurs (i) at the InO₆ octahedral layer and (ii) halfway in the wurtzite type region, where the inversion boundary is built by Ga³⁺ in trigonal bipyramidal coordination with a long Ga–O_apical distance of 2.19(1) Å. The site occupation of Zn²⁺ and Ga³⁺, respectively, was confirmed by bond valence sum calculations. The compounds described here have the same structural charactistics as other known members with general formula ARO₃(ZnO)_m with m = integer.     

On the Binary Compound YbGa5

YbGa₅ was characterized in course of a re‐investigation of the Yb—Ga system in the range between 0 and 20 at. % Yb. The compound can be described as a defect variant of the Ce₂Ga₁₀Ni structure type (space group I4/mmm, a = 430.59(4) pm, c = 2587.1(4) pm). The special feature of the crystal structure is given by local disorder within the gallium network. From magnetic susceptibility, ytterbium is in the valence state 2+.     

新Schiff碱SAAQ的合成及其分析应用研究(Ⅰ)——荧光光度法测定镓

常用于测定镓的荧光试剂有8-羟基喹啉类、Schiff碱类、偶氮类及黄酮类等^[1～8]。而水杨醛缩-8-氨基喹啉(简称SAAQ)的合成及分析应用研究尚未见报道.本文研究了该试剂的合成方法及其分析应用.     

X‐Ray Photoemission Studies of the Ternary Intermetallic Compounds Li2MGa and LiMGa2 (M = Rh,Pd, Ir,Pt)

X‐ray photoelectron and x‐ray excited Auger spectra were measured for the intermetallic compounds LiMGa₂ and Li₂MGa (M = Rh, Pd, Ir, Pt). The valence band spectra exhibit characteristic differences in the location of the M d‐band between group 9 elements (Rh, Ir) and group 10 elements (Pd, Pt) on one side and between LiMGa₂ and Li₂MGa on the other. The experimentally observed differences are in excellent agreement with results from band structure calculations. The combination of binding energy shifts with Auger kinetic energy shifts allowed a separation of initial and final state contributions. Core hole screening is very efficient in accordance with the metallic character of the investigated phases. The magnitude of the screening correlates with the theoretically predicted composition of the density of states at the Fermi level. Application of Wertheim's electrostatic model allowed to estimate the charge distribution for LiRhGa₂ and Li₂RhGa. The sign of the charges agrees with expectations that result from the Extended Zintl Concept. The results show, how dangerous it is to draw conclusions on the chemistry of such systems from photoemission data alone.     

GaGa‐ und AlFe‐Mehrfachbindungen? Ein Interpretationsversuch auf der Grundlage von Kraftkonstanten

GaGa and AlFe Multiple Bonds? An Attempt of Interpretation on the Basis of Force Constants Comparison of force constant values given by DFT frequency calculations shows that GaGa‐bonds in Ga₂H₄^2– and Ga₂H₂^2– are only slightly strengthened with respect to the GaGa‐single bond in Ga₂H₆^2–. On the other hand FeAl bonds in compounds like CpAlFe(CO)₄ are interpreted as double bonds.