Growth of small GeO 2 single crystals on a polyvinyl chloride substrate at room temperature using oversaturate aqueous solution

2019 ◽  
Vol 102 (7) ◽  
pp. 12-16
Author(s):  
Kiyoshi Kobayashi ◽  
Tohru S. Suzuki
1987 ◽  
Vol 42 (11) ◽  
pp. 1313-1320 ◽  
Author(s):  
Surendra Sharma ◽  
Norbert Weiden ◽  
Alarich Weiss

By 205Tl and 207Pb NM R the chemical shift in polycrystalline samples of binary halides AX, BX2 and ternary halides ABX3 (A = Cs, Tl; B = Pb; X = Br, I) was studied at room temperature. The chemical shift tensors δ ( 205Tl) and δ (207Pb) were determined in magnitude and orientation on single crystals of the orthorhombic TlPbI3. The components of the δ(205Tl) tensor are δx (205Tl) || a = 611ppm; δy (205Tl) || b = 680 ppm; δZ(205Tl) || c = 1329 ppm; δiso(205Tl) = 873.3 ppm (with respect to 3.4 molar aqueous solution of TlOOCCH3). The chemical shift tensor of 207Pb in TlPbI3 shows two orientations. One of them is: δx (207Pb) = 3760 ppm, inclined 30° from b towards c, δy(207Pb) || a = 3485 ppm, δz(207Pb) = 2639 ppm inclined 120° from b towards c. δiso(207Pb) = 3295 ppm (with respect to saturated aqueous solution of Pb(NO3)2). The results are discussed with respect to the crystal structure and a model to explain orientation and anisotropy of the tensors δ(205Tl) and δ(207Pb) in TlPbI3 is proposed.In the system CsPbBr3-x Ix δ(207Pb) was studied on polycrystalline samples. The chemical shift increases with increasing x and negative excess shift is observed.


1999 ◽  
Vol 54 (11) ◽  
pp. 1363-1370 ◽  
Author(s):  
Kai Landskron ◽  
Wolfgang Schnick

1,1,1,3,3,3-Hexaamino-1λ5,3λ5-diphosphazenium bromide [(NH2)3PNP(NH2)3]Br, nitrate [(NH2)3PNP(NH2)3][NO3], and toluene-4-sulfonate [(NH2)3PNP(NH2)3][CH3C6H4SO3] have been prepared by anion exchange in aqueous solution. Single crystals were obtained from acetonitrile solutions in a temperature gradient between 60 °C and room temperature. The crystal structures were determined by single crystal X-ray methods at room temperature. ([(NH2)3PNP(NH2)3]Br: P1̄̄ , Z = 2, a = 596.2( 1 ),b = 744.5( 1), c = 1114.4( 1) pm, α = 108.78( 1), β = 104.18(1), γ = 90.64(1)°, R 1 = 0.048, wR2 = 0.104; [(NH2)3PNP(NH2)3][NO3]: P1̄̄, Z = 2, a = 550.9( 1), b = 796.3( 1), c = 1115.7( 1) pm, α = 94.45( 1), β= 99.55( 1), γ = 101,53( 1)°, R1 = 0.033, wR2 = 0.095; [(NH2)3PNP(NH2)3][CH3C6H4SO3]: P21/c, Z = 4, a = 804.1(1), b = 596.1(1), c = 3218.7(3) pm, β = 94.59(1)°, R1 = 0.052, wR2 = 0.136). In the solid the three salts consist of discrete [(NH2)3PNP(NH2)3]+ cations and their corresponding anions. The PN4 tetrahedra in [(NH2)3PNP(NH2)3]Br are staggered, while in [(NH2)3PNP(NH2)3][NO3] the eclipsed conformation is preferred. The PN4 tetrahedra of [(NH2)3PNP(NH2)3][CH3C6H4SO3] show gauche conformation.


2020 ◽  
Author(s):  
Roberto Köferstein

Blue monoclinic single crystals of the novel one-dimensional [H3N-(CH2)6-NH3][Cu(H2O)2(urea)(µ2-C6(COO)4 (COOH)2)]*H2O coordination polymer have been prepared in aqueous solution at room temperature in the presence of 1,6-diaminohexane and urea. Space group P21/n (no. 14) with a = 958.48(9), b = 1465.74(11), c = 1821.14(12) pm, beta = 97.655(8)°. The Cu2+ cation is coordinated in a square pyramidal manner by two oxygen atoms stemming from the dihydrogen mellitate tetraanion, one oxygen atom from the urea molecule, and two water molecules. The Cu−O distances are between 193.3(2) and 229.4(2) pm. The connection between Cu2+ and [C6(COO)4(COOH)2]4-


Author(s):  
N.J. Long ◽  
M.H. Loretto ◽  
C.H. Lloyd

IntroductionThere have been several t.e.m. studies (1,2,3,4) of the dislocation arrangements in the matrix and around the particles in dispersion strengthened single crystals deformed in single slip. Good agreement has been obtained in general between the observed structures and the various theories for the flow stress and work hardening of this class of alloy. There has been though some difficulty in obtaining an accurate picture of these arrangements in the case when the obstacles are large (of the order of several 1000's Å). This is due to both the physical loss of dislocations from the thin foil in its preparation and to rearrangement of the structure on unloading and standing at room temperature under the influence of the very high localised stresses in the vicinity of the particles (2,3).This contribution presents part of a study of the Cu-Cr-SiO2 system where age hardening from the Cu-Cr and dispersion strengthening from Cu-Sio2 is combined.


Author(s):  
H. P. Karnthaler ◽  
A. Korner

In f.c.c. metals slip is observed to occur generally on {111} planes. Glide dislocations on intersecting {111} planes can react with each other and form Lomer-Cottrell locks which lie along a <110> direction and are sessile since they are split on two {111} planes. Cottrell already pointed out that these dislocations could glide on {001} planes if they were not split. The first study of this phenomenon has been published recently. It is the purpose of this paper to report some interesting new details of the dislocations gliding on {001} planes in pure Ni, Cu, and Ag deformed at room temperature.Single crystals are grown with standard orientation and strained into stage II. The crystals are sliced parallel to the (001) planes. The dislocation structure is studied by TEM and the Burgers vectors ḇ and glide planes of the dislocations are determined unambiguously.In Fig.l primary P and secondary S dislocations react and form composite dislocations K.


2019 ◽  
Author(s):  
Chem Int

Optically transparent single crystals of potassium acid phthalate (KAP, 0.5 g) 0.05 g and 0.1 g (1 and 2 mol %) trytophan were grown in aqueous solution by slow evaporation technique at room temperature. Single crystal X- ray diffraction analysis confirmed the changes in the lattice parameters of the doped crystals. The presence of functional groups in the crystal lattice has been determined qualitatively by FTIR analysis. Optical absorption studies revealed that the doped crystals possess very low absorption in the entire visible region. The dielectric constant has been studied as a function of frequency for the doped crystals. The thermal stability was evaluated by TG-DSC analysis.


Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1897
Author(s):  
Hideyasu China ◽  
Nami Kageyama ◽  
Hotaka Yatabe ◽  
Naoko Takenaga ◽  
Toshifumi Dohi

We report a convenient and practical method for the preparation of nonexplosive cyclic hypervalent iodine(III) oxidants as efficient organocatalysts and reagents for various reactions using Oxone® in aqueous solution under mild conditions at room temperature. The thus obtained 2-iodosobenzoic acids (IBAs) could be used as precursors of other cyclic organoiodine(III) derivatives by the solvolytic derivatization of the hydroxy group under mild conditions of 80 °C or lower temperature. These sequential procedures are highly reliable to selectively afford cyclic hypervalent iodine compounds in excellent yields without contamination by hazardous pentavalent iodine(III) compound.


CrystEngComm ◽  
2021 ◽  
Author(s):  
Maryam Bari ◽  
Hua Wu ◽  
Alexei A. Bokov ◽  
Rana Faryad Ali ◽  
Hamel N. Tailor ◽  
...  

Growth of MAPbX3 (X = I, Br, and Cl) single crystals by room temperature crystallization (RTC) method, and the crystallization pathway illustrated by the solubility curve of MAPbCl3 in DMSO, compared with inverse temperature crystallization (ITC) method.


Sign in / Sign up

Export Citation Format

Share Document