Organic/Inorganic Superlattices: Structural and Optical Properties

1994 ◽  
Vol 351 ◽  
Author(s):  
Shizuo Tokito ◽  
J. Sakata ◽  
Y. Taga

ABSTRACTA new class of superlattices consisting of alternating layers of organic and inorganic materials has been prepared from 8-hydroxyquinoline aluminium (Alq), copper phthalocyanine (CuPc), 3,4,9,10-perylenetetracarboxylic diimide (PTCDI) and MgF2 by molecular beam deposition. Small-angle x-ray diffraction data and cross-sectional transmission electron micrograph of the superlattices reveal that the superlattices have layered structure throughout the entire stack. From comparison of the x-ray diffraction patterns, it is found that the interface roughness between organic and MgF2 layers depends on the materials for organic layers. High-angle x-ray diffraction data indicate that there is a structural ordering in the CuPc and PTCDI layers. From the optical absorption and photoluminescence measurements, it is found that the exciton energy of Alq shifts to higher energy with decreasing Alq layer thickness.

2014 ◽  
Vol 21 (6) ◽  
pp. 1378-1383 ◽  
Author(s):  
Yuki Sekiguchi ◽  
Masaki Yamamoto ◽  
Tomotaka Oroguchi ◽  
Yuki Takayama ◽  
Shigeyuki Suzuki ◽  
...  

Using our custom-made diffraction apparatus KOTOBUKI-1 and two multiport CCD detectors, cryogenic coherent X-ray diffraction imaging experiments have been undertaken at the SPring-8 Angstrom Compact free electron LAser (SACLA) facility. To efficiently perform experiments and data processing, two software suites with user-friendly graphical user interfaces have been developed. The first is a program suite namedIDATEN, which was developed to easily conduct four procedures during experiments: aligning KOTOBUKI-1, loading a flash-cooled sample into the cryogenic goniometer stage inside the vacuum chamber of KOTOBUKI-1, adjusting the sample position with respect to the X-ray beam using a pair of telescopes, and collecting diffraction data by raster scanning the sample with X-ray pulses. NamedG-SITENNO, the other suite is an automated version of the originalSITENNOsuite, which was designed for processing diffraction data. These user-friendly software suites are now indispensable for collecting a large number of diffraction patterns and for processing the diffraction patterns immediately after collecting data within a limited beam time.


2014 ◽  
Vol 950 ◽  
pp. 48-52
Author(s):  
De Gui Li ◽  
Ming Qin ◽  
Liu Qing Liang ◽  
Zhao Lu ◽  
Shu Hui Liu ◽  
...  

The Al2M3Y(M=Cu, Ni) compound was synthesized by arc melting under argon atmosphere. The high-quality powder X-ray diffraction data of Al2M3Y have been presented. The refinement of the X-ray diffraction patterns for the Al2M3Y compound show that the Al2M3Y has hexagonal structure, space groupP6/mmm(No.191), with a = b = 5.1618(2) Å, c = 4.1434(1) Å,V= 95.6 Å3,Z= 1,ڑx= 5.7922 g/cm3,F30= 155.5(0.0057, 34), RIR = 2.31 for Al2Cu3Y, and with a = b = 5.0399(1) Å, c = 4.0726(1) Å,V= 89.59 Å3,Z= 1,ڑx= 5.9118 g/cm3,F30= 135.7(0.0072, 30), RIR = 2.54 for Al2Ni3Y.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Wei-Lin Wang ◽  
Chia-Ti Wang ◽  
Wei-Chun Chen ◽  
Kuo-Tzu Peng ◽  
Ming-Hsin Yeh ◽  
...  

Ta/TaN bilayers have been deposited by a commercial self-ionized plasma (SIP) system. The microstructures of Ta/TaN bilayers have been systematically characterized by X-ray diffraction patterns and cross-sectional transmission electron microscopy. TaN films deposited by SIP system are amorphous. The crystalline behavior of Ta film can be controlled by the N concentration of underlying TaN film. On amorphous TaN film with low N concentration, overdeposited Ta film is the mixture ofα- andβ-phases with amorphous-like structure. Increasing the N concentration of amorphous TaN underlayer successfully leads upper Ta film to form pureα-phase. For the practical application, the electrical property and reliability of Cu interconnection structure have been investigated by utilizing various types of Ta/TaN diffusion barrier. The diffusion barrier fabricated by the combination of crystallizedα-Ta and TaN with high N concentration efficiently reduces the KRc and improves the EM resistance of Cu interconnection structure.


1997 ◽  
Vol 12 (3) ◽  
pp. 134-135
Author(s):  
Liangqin Nong ◽  
Lingmin Zeng ◽  
Jianmin Hao

The compound DyNiSn has been studied by X-ray powder diffraction. The X-ray diffraction patterns for this compound at room temperature are reported. DyNiSn is orthorhombic with lattice parameters a=7.1018(1) Å, b=7.6599(2) Å, c=4.4461(2) Å, space group Pna21 and 4 formula units of DyNiSn in unit cell. The Smith and Snyder Figure-of-Merit F30 for this powder pattern is 26.7(0.0178,63).


2014 ◽  
Vol 47 (1) ◽  
pp. 215-221 ◽  
Author(s):  
Devinder Singh ◽  
Yifeng Yun ◽  
Wei Wan ◽  
Benjamin Grushko ◽  
Xiaodong Zou ◽  
...  

Electron diffraction is a complementary technique to single-crystal X-ray diffraction and powder X-ray diffraction for structure solution of unknown crystals. Crystals too small to be studied by single-crystal X-ray diffraction or too complex to be solved by powder X-ray diffraction can be studied by electron diffraction. The main drawbacks of electron diffraction have been the difficulties in collecting complete three-dimensional electron diffraction data by conventional electron diffraction methods and the very time-consuming data collection. In addition, the intensities of electron diffraction suffer from dynamical scattering. Recently, a new electron diffraction method, rotation electron diffraction (RED), was developed, which can overcome the drawbacks and reduce dynamical effects. A complete three-dimensional electron diffraction data set can be collected from a sub-micrometre-sized single crystal in less than 2 h. Here the RED method is applied forab initiostructure determination of an unknown complex intermetallic phase, the pseudo-decagonal (PD) quasicrystal approximant Al37.0(Co,Ni)15.5, denoted as PD2. RED shows that the crystal is F-centered, witha= 46.4,b= 64.6,c= 8.2 Å. However, as with other approximants in the PD series, the reflections with oddlindices are much weaker than those withleven, so it was decided to first solve the PD2 structure in the smaller, primitive unit cell. The basic structure of PD2 with unit-cell parametersa= 23.2,b= 32.3,c= 4.1 Å and space groupPnmmhas been solved in the present study. The structure withc= 8.2 Å will be taken up in the near future. The basic structure contains 55 unique atoms (17 Co/Ni and 38 Al) and is one of the most complex structures solved by electron diffraction. PD2 is built of characteristic 2 nm wheel clusters with fivefold rotational symmetry, which agrees with results from high-resolution electron microscopy images. Simulated electron diffraction patterns for the structure model are in good agreement with the experimental electron diffraction patterns obtained by RED.


1971 ◽  
Vol 54 (6) ◽  
pp. 1406-1419
Author(s):  
E Okkerse ◽  
A De Leenheer ◽  
A Heyndrickx

Abstract Isolation and crystallization procedures have been developed for butyrophenones as free substances and from pharmaceutical formulations, namely ampoules, coated tablets, drops, and tablets. Crystallization as free bases, picrates, picrolonates, chlorhydrates, bromates, sulfates, and phosphates was attempted for all compounds. For the crystalline derivatives, the X-ray diffraction data were obtained by the Debye-Scherrer powder technique with photographic recording. The products have been classified according to their X-ray data, using “Hanawalt’s three strongest lines index” and the “innermost line index” systems. The butyrophenones could be identified with certainty by direct comparison of the X-ray diffraction patterns of compounds isolated from dosage forms with reference patterns.


2021 ◽  
pp. 1-5
Author(s):  
Junyan Zhou ◽  
Congcong Chai ◽  
Munan Hao ◽  
Xin Zhong

A new organic–inorganic hybrid lithium m-phenylenediamine sulfate (LPS), Li2(C6H10N2)(SO4)2, was synthesized under aqueous solution conditions. The X-ray powder diffraction study determined that the title compound crystallized in a monoclinic system at 300 K, with unit-cell parameters a = 7.8689(6) Å, b = 6.6353(5) Å, c = 11.8322(10) Å, β = 109.385(3) °, V = 582.77(8) Å3. Indexing of the diffraction patterns collected from 100 to 600 K reveals that LPS has no structural phase transition within the measured temperature range, and the volume expansion coefficient is approximately 2.79 × 10−5 K−1. The crystal structure was solved based on the single-crystal diffraction data with space group P21/m. Lithium and SO42− are found to form quasi-two-dimensional anti-fluorite [LiSO4] layers stacking along the c-axis, with m-phenylenediamine molecules inserted in the anti-fluorite layers and forming hydrogen bonds to the SO42−. This explains a moderate anisotropic expansion in LPS.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Ramesh Thimmasandra Narayan

β-phases of nickel hydroxide and cobalt hydroxide samples crystallize in cadmium iodide type structure. β-cobalt hydroxide on oxidation generates β-CoOOH which crystallized in 3R1 polytype while the structure of β-phase of NiOOH polytype is less well understood. β- and βbc-phases of nickel hydroxide samples were prepared by using ammonium hydroxide and sodium hydroxide as precipitating agents. Powder X-ray diffraction data shows that β-phase of nickel hydroxide is perfectly crystalline in nature while βbc-phase of nickel hydroxide is poorly ordered. β- and βbc-phases of nickel hydroxide samples were subjected to chemical oxidation using sodium hypochlorite. The oxidized phases of β- and βbc-phases of nickel oxyhydroxide are highly disordered and the broadening of reflections in the powder X-ray diffraction patterns is due to the presence of structural disorder, variations in the crystallite size, and strain. On reduction of β- and βbc-phases of nickel oxyhydroxide, the powder X-ray diffraction patterns visually match the powder X-ray diffraction data of the pristine phases of β- and βbc-phases of nickel hydroxide indicating that the β-phase of nickel hydroxide does not transform to βbc-phase of nickel hydroxide, but the particle sizes are significantly affected.


Open Physics ◽  
2008 ◽  
Vol 6 (3) ◽  
Author(s):  
Hua Li ◽  
Jianping Sang ◽  
Chang Liu ◽  
Hongbing Lu ◽  
Juncheng Cao

AbstractSingle crystalline ZnO film is grown on GaN/sapphire (0001) substrate by molecular beam epitaxy. Ga2O3 is introduced into the ZnO/GaN heterostructure intentionally by oxygen-plasma pre-exposure on the GaN surface prior to ZnO growth. The crystalline orientation and interfacial microstructure are characterized by X-ray diffraction and transmission electron microscopy. X-ray diffraction analysis shows strong c-axis preferred orientation of the ZnO film. Cross-sectional transmission electron microscope images reveal that an additional phase is formed at the interface of ZnO/GaN. Through a comparison of diffraction patterns, we confirm that the interface layer is monoclinic Ga2O3 and the main epitaxial relationship should be $$ (0001)_{ZnO} \parallel (001)_{Ga_2 O_3 } \parallel (0001)_{GaN} $$ and $$ [2 - 1 - 10]_{ZnO} \parallel [010]_{Ga_2 O_3 } \parallel [2 - 1 - 10]_{GaN} $$.


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