Hydrogen-Induced Defects of Subsurface Layer in ZnO Single Crystal Probed by a Slow Positron Beam

2012 ◽  
Vol 733 ◽  
pp. 232-235 ◽  
Author(s):  
X.D. Xue ◽  
T. Wang ◽  
J. Jiang ◽  
P.H. Li ◽  
Y.F. Liu ◽  
...  
Keyword(s):  
Single Crystal ◽  
Subsurface Layer ◽  
Positron Beam ◽  
X Ray Diffraction ◽  
Slow Positron ◽  
X Ray ◽  
S Parameter ◽  
Induced Defects ◽  
Zno Single Crystal ◽  
Deformation Layer

Hydrogen-induced defects of ZnO single crystals electrochemically charged with hydrogen have been investigated by positron beam-based Doppler broadening spectroscopy, X-ray diffraction (XRD) and optical microscopy (OM). XRD and OM results indicated that a deformation layer was formed due to hydrogen-induced structural change at the subsurface of ZnO single crystal. Slow positron beam measurements showed that this deformation layer contained many defects, such as dislocations and Zn vacancies, which led to increase of S parameter.

CHARACTERIZATION OF Ni-RICH INTERMETALLIC COMPOUND Ni3Al FILMS WITH SLOW POSITRON BEAM

2009 ◽  
Vol 23 (26) ◽  
pp. 3097-3106 ◽  
Author(s):  
JIANDANG LIU ◽  
HUIMIN WENG ◽  
XIANGLEI CHEN ◽  
HUAIJIANG DU ◽  
BANGJIAO YE ◽  
...  
Keyword(s):  
Grain Size ◽  
Intermetallic Compound ◽  
Effective Diffusion ◽  
Positron Beam ◽  
Vacancy Cluster ◽  
X Ray Diffraction ◽  
Slow Positron ◽  
X Ray ◽  
S Parameter

Ni -rich intermetallic compound Ni 3 Al films were deposited using the dual-target magnetron co-sputtering method. The grain-boundary and grain-size characteristics of the as-deposited and post-annealed Ni 3 Al films were investigated using a slow positron beam. The results demonstrate a distinct change of S-parameter and positron effective diffusion length L eff values as samples were annealed at different ambient atmospheres and temperatures. It shows that the positron trapping center is mainly associated with intergranular vacancies, and changes to either the vacancy cluster size or the grain size have been invoked to explain the changes of the values of the S-parameter and L eff . Ni -rich oxygen- Ni 3 Al films were also studied. All films were identified using X-ray diffraction and the results confirm the conclusion obtained by the slow positron beam.

Fabrication and Magneto-Transport Properties of Zn0.88-xMgxMn0.12O/ZnO Heterostructures Grown on ZnO Single-Crystal Substrates

2010 ◽  
Vol 75 ◽  
pp. 1-8
Author(s):  
Keiichiro Masuko ◽  
Tatsuru Nakamura ◽  
Atsushi Ashida ◽  
Takeshi Yoshimura ◽  
Norifumi Fujimura
Keyword(s):  
Single Crystal ◽  
Transport Properties ◽  
Flat Surface ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Force ◽  
Brillouin Function ◽  
Atomic Force Microscope Observation ◽  
Zno Single Crystal ◽  
Atomically Flat

The transport properties of Zn0.88-xMgxMn0.12O/ZnO modulation-doped heterostructures (x≤0.15) were investigated. The heterostructures were fabricated on ZnO single-crystal substrates by a pulsed laser deposition system. Atomic force microscope observation and X-ray diffraction analysis suggested that Zn0.88-xMgxMn0.12O layers have atomically flat surface and excellent crystallinity. The results of Hall measurement for Zn0.88-xMgxMn0.12O/ZnO modulation-doped heterostructure with x=0.075 revealed that the carrier concentration and the electron mobility were 5.1×1012cm-2 and 800 cm2/Vs at 10 K, respectively, suggesting that the carrier confinement effect exits at the heterointerface between Zn0.88-xMgxMn0.12O barrier layer and ZnO channel layer. In the magnetoresistance (MR) measurement at 1.85 K, a positive MR behavior was observed below 0.5 T, while a negative MR behavior was recognized above 0.5 T. The slope of the positive MR decreased with increasing the temperature and was well fitted to the Brillouin function with S=5/2. The electrical and magneto-transport properties were very similar to those of Zn0.88Mn0.12O/ZnO heterostructures without doping Mg.

Positron Beam Study of Co Doped ZnO Films Prepared by PLD

2008 ◽  
Vol 607 ◽  
pp. 102-104 ◽  
Author(s):  
Hong Feng Ren ◽  
Hui Min Weng ◽  
Bang Jiao Ye ◽  
Rong Dian Han ◽  
Hui Li ◽  
...  
Keyword(s):  
Diffusion Length ◽  
Effective Diffusion ◽  
Positron Beam ◽  
Zno Films ◽  
Defect Structures ◽  
X Ray Diffraction ◽  
Slow Positron ◽  
X Ray ◽  
Doped Zno ◽  
Co Doped

Slow positron beam are used to study defect structures in Co doped and undoped ZnO films prepared by Pulsed Laser Deposition (PLD) at 400°C, 600°C, 700°C on c-plane sapphire. Comparing with ZnO samples, Co doped ZnO samples have larger positron effective diffusion length (Leff), which change in different tendencies depending on the growth temperature. Crystal structures of the samples are investigated by X-ray diffraction (XRD) and wurtzite ZnO could be observed in Co doped samples.

scholarly journals Optical and structural characterization of antimony doped ZnO single crystal.

2014 ◽  
Vol 70 (a1) ◽  
pp. C1417-C1417
Author(s):  
Gabriel Juarez Diaz ◽  
Javier Martinez Juarez ◽  
Ramon Peña Sierra ◽  
Primavera Lopez Salazar ◽  
Jorge Contreras Rascon ◽  
...  
Keyword(s):  
Single Crystal ◽  
Structural Modification ◽  
Atomic Diffusion ◽  
X Ray Diffraction ◽  
Reciprocal Space Mapping ◽  
X Ray ◽  
Radiative Transitions ◽  
Zno Single Crystal

We present the optical and structural study of the antimony doped zinc oxide (ZnO) performed by atomic diffusion. Diffusion is carried out at a temperature of 10000C for periods of 1, 2 and 4 hrs from a solid source prepared by partial oxidation of antimony, characterizing each step of the process was performed by photoluminescence (PL) and x-ray diffraction (XRD). The characterization by photoluminescence shows the effect of doping with antimony in radiative transitions caused by the creation of impurity levels. Doped samples were analyzed by high resolution diffraction and reciprocal space mapping which revealed the structural modification of the quality of the single crystal produced by the introduction of antimony. The results indicate that the antimony is introduced fully the volume of ZnO and does not modify the quality of the crystal.

Electron Microscopy of Shock Loaded Polycrystalline Beryllium

1974 ◽  
Vol 32 ◽  
pp. 506-507 ◽  
Author(s):  
J. M. Galbraith ◽  
L. E. Murr ◽  
A. L. Stevens
Keyword(s):  
Electron Microscopy ◽  
Wave Propagation ◽  
Structural Change ◽  
Single Crystal ◽  
Diffraction Pattern ◽  
Shock Loading ◽  
Slip Systems ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
X Ray

Uniaxial compression tests and hydrostatic tests at pressures up to 27 kbars have been performed to determine operating slip systems in single crystal and polycrystal1ine beryllium. A recent study has been made of wave propagation in single crystal beryllium by shock loading to selectively activate various slip systems, and this has been followed by a study of wave propagation and spallation in textured, polycrystal1ine beryllium. An alteration in the X-ray diffraction pattern has been noted after shock loading, but this alteration has not yet been correlated with any structural change occurring during shock loading of polycrystal1ine beryllium.This study is being conducted in an effort to characterize the effects of shock loading on textured, polycrystal1ine beryllium. Samples were fabricated from a billet of Kawecki-Berylco hot pressed HP-10 beryllium.

Crystal structure of an inclusion complex between chiral monoaza-15-crown-5 and S(–)-1-phenyl-ethyl ammonium percholorate

2003 ◽  
Vol 218 (5) ◽  
Author(s):  
Süheyla Özbey ◽  
F. B. Kaynak ◽  
M. Toğrul ◽  
N. Demirel ◽  
H. Hoşgören
Keyword(s):  
Crystal Structure ◽  
Inclusion Complex ◽  
Single Crystal ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
New Type

AbstractA new type of inclusion complex, S(–)-1 phenyl ethyl ammonium percholorate complex of R-(–)-2-ethyl - N - benzyl - 4, 7, 10, 13 - tetraoxa -1- azacyclopentadecane, has been prepared and studied by NMR, IR and single crystal X-ray diffraction techniques. The compound crystallizes in space group

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