scholarly journals Origin of Difference in Photocatalytic Activity of ZnO (002) Grown on a- and c-Face Sapphire

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Guoqiang Li ◽  
Bingyang Sun ◽  
Yali Wang ◽  
Zhou Wu ◽  
Weifeng Zhang
Keyword(s):  
Photocatalytic Activity ◽  
Pulsed Laser ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Laser Deposition ◽  
Surface Conductance ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Zno Film ◽  
X Ray

The oriented (002) ZnO films were grown on a- and c-face sapphire by pulsed laser deposition. The X-ray diffraction analysis revealed that the oriented (002) ZnO films were epitaxially grown on the substrate successfully. The sample on a-face sapphire had higher crystal quality. However, the photocatalytic activity for Rhodamine B degradation of ZnO film on c-face sapphire was higher than that on a-face sapphire. The Raman spectrum and XPS analysis suggested that the sample on a-face sapphire had higher concentration of defects. The result of the contact angle measurement revealed that the sample on c-face sapphire had higher surface energy. And the investigation of the surface conductance implied that the higher light conductance was helpful for the photocatalytic activity.

THE GD CONCENTRATION DEPENDENCE OF THE MAGNETIC PROPERTIES OF ROOM TEMPERATURE FERROMAGNETIC ZNO:GD SEMICONDUCTOR

2009 ◽  
Vol 23 (17) ◽  
pp. 3550-3555 ◽  
Author(s):  
S. T. LIM ◽  
W. D. SONG ◽  
K. L. TEO ◽  
T. LIEW ◽  
T. C. CHONG
Keyword(s):  
Magnetic Properties ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Solubility Limit ◽  
Laser Deposition ◽  
Implantation Technique ◽  
Zno Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural And Magnetic Properties

We present structural and magnetic properties of ZnO films doped with rare-earth Gd ions at various concentrations, achieved by ion implantation technique and pulsed laser deposition (PLD) on ZnO (0001) single crystals and sapphire. X-ray diffraction shows Gd doping in ZnO and crystal quality degrades with increasing Gd concentration. Magnetization as a function of temperature revealed a positive magnetization at 305 K and a concave trend was observed for all samples for both implanted and PLD grown samples. The highest saturation magnetization was achieved for Gd concentration of x = 7.9 % (0.7 µ B / Gd ) and at dosage of 9.0 × 1015 cm -2 (2.6 µ B / Gd ) for the PLD grown and implanted samples, respectively. We believe that the Gd ion solubility limit in the implanted and PLD grown samples, of around 3% and 7.9%, respectively, are reached.

Heteroepitaxial growth of ZnO films on Gd3Ga5O12 garnet substrates

2012 ◽  
Vol 1394 ◽  
Author(s):  
Yosuke Ono ◽  
Hiroaki Matsui ◽  
Hitoshi Tabata
Keyword(s):  
Single Phase ◽  
Laser Deposition ◽  
Zno Films ◽  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
Zno Film ◽  
Structural And Optical Properties ◽  
X Ray ◽  
Out Of Plane ◽  
Sharp Interfaces

ABSTRACTThis study focused on structural and optical properties of ZnO films grown epitaxially on Gd3Ga5O12 substrates. ZnO films (a = 3.2439 Å and c = 5.2036 Å) were deposited on the (001) and (111) planes of Gd3Ga5O12 (GGG: a = 12.383 Å) garnet substrates by a pulsed laser deposition method. From out-of-plane and in-plane X-ray diffraction measurements, the obtained ZnO films showed a single phase with the (0001) orientation on the GGG (001) and (111) substrates. The epitaxial relations between the ZnO film and GGG (001) substrate were [10-10] ZnO ‖ [100] GGG and [10-10] ZnO ‖ [010] GGG, while the epitaxial relations between the ZnO film and GGG (111) substrate were [10-10] ZnO ‖ [11-2] GGG ±21°. Furthermore, transmittance electron microscopy revealed sharp interfaces between ZnO films and GGG substrates. From photoluminescent spectra, the ZnO films showed donor bound emissions superimposed with free excitons at a low temperature of 10 K.

Polydomain Structure of Epitaxial PbTiO3 films on MgO

1997 ◽  
Vol 493 ◽  
Author(s):  
S. P. Alpay ◽  
A. S. Prakash ◽  
S. Aggarwal ◽  
R. Ramesh ◽  
A. L. Roytburd ◽  
...  
Keyword(s):  
Domain Structure ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Theoretical Predictions ◽  
The Stability ◽  
Increasing Temperature ◽  
Stable Domains ◽  
Domain Stability

ABSTRACTA PbTiO3(001) film grown on MgO(001) by pulsed laser deposition is examined as an example to demonstrate the applications of the domain stability map for epitaxial perovskite films which shows regions of stable domains and fractions of domains in a polydomain structure. X-ray diffraction studies indicate that the film has a …c/a/c/a… domain structure in a temperature range of °C to 400°C with the fraction of c-domains decreasing with increasing temperature. These experimental results are in excellent agreement with theoretical predictions based on the stability map.

Frequency and Temperature Dependence of Dielectric Properties of Orthorhombic HoMnO3 Thin Films

2014 ◽  
Vol 1025-1026 ◽  
pp. 427-431
Author(s):  
Ping Gao ◽  
Wei Zhang ◽  
Wei Tian Wang
Keyword(s):  
Dielectric Properties ◽  
Pulsed Laser ◽  
Signal Amplitude ◽  
Debye Model ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Cole Diagram

Orthorhombic HoMnO3 films were prepared epitaxially on Nb-doped SrTiO3 single crystal substrates by using pulsed laser deposition technique. The films showed perfectly a-axis crystallographic orientations. X-ray diffraction and atomic force microscopy were used to characterize the films. The complex dielectric properties were measured as functions of frequency (40 Hz~1 MHz) and temperature (80 K~300 K) with a signal amplitude of 50 mv. The respective dielectric relaxation peaks shifted to higher frequency as the measuring temperature increased, with the same development of real part of the complex permittivity. The cole-cole diagram was obtained according to the Debye model, and the effects of relaxation process were discussed.

Study of Raman Spectrum of Fe Doped CeO2 Thin Films Grown by Pulsed Laser Deposition

2010 ◽  
Vol 123-125 ◽  
pp. 375-378 ◽  
Author(s):  
Ram Prakash ◽  
Shalendra Kumar ◽  
Chan Gyu Lee ◽  
S.K. Sharma ◽  
Marcelo Knobel ◽  
...  
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Single Phase ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Fe Doping ◽  
Full Width ◽  
Deposition Technique ◽  
X Ray Diffraction ◽  
X Ray

Ce1-xFexO2 (x=0, 0.01, 0.03 and 0.0 5) thin films were grown by pulsed laser deposition technique on Si and LaAlO3 (LAO) substrates. These films were deposited in vacuum and 200 mTorr oxygen partial pressure for both the substrates. These films were characterized by x-ray diffraction XRD and Raman spectroscopy measurements. XRD results reveal that these films are single phase. Raman results show F2g mode at ~466 cm-1 and defect peak at 489 cm-1 for film that deposited on LAO substrates, full width at half maximum (FWHM) is increasing with Fe doping for films deposited on both the substrates.

Properties of Nano-ZnO Films Deposited by RF Magnetron Sputtering for SAW Biosensors

2011 ◽  
Vol 418-420 ◽  
pp. 293-296
Author(s):  
Qiu Yun Fu ◽  
Peng Cheng Yi ◽  
Dong Xiang Zhou ◽  
Wei Luo ◽  
Jian Feng Deng
Keyword(s):  
Magnetron Sputtering ◽  
Deposition Time ◽  
Rf Magnetron Sputtering ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Zno Film ◽  
Nano Zno ◽  
Axis Orientation ◽  
X Ray

Abstract. In this article, nano-ZnO films were deposited on SiO2/Si (100) substrates by RF (radio frequency) magnetron sputtering using high purity (99.99%) ZnO target. The effects of deposition time and annealing temperature have been investigated. XRD (X-ray diffraction) and FSEM (Field Emission Scanning Electron Microscopy) were employed to characterize the quality of the films. The results show that the ZnO film with thickness of 600nm annealed at 900°C has higher quality of both C-axis orientation and crystallization. And for the Zone film with thickness of 300nm annealed at 850°C, the quality of both C-axis orientation and crystallization is higher than that annealed at 900°C and 950°C.

Control of Crystallinity of Hydroxyapatite Sheet

2013 ◽  
Vol 583 ◽  
pp. 47-50 ◽  
Author(s):  
Masanobu Kusunoki ◽  
Taiyo Matsuda ◽  
Naoki Fujita ◽  
Yasuhiro Sakoishi ◽  
Ryou Iguchi ◽  
...  
Keyword(s):  
Cell Culture ◽  
Annealing Temperature ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
Free Standing ◽  
X Ray ◽  
Electric Oven ◽  
Diffraction Peaks ◽  
Conventional Annealing

A technique to control the crystallinity of hydroxyapatite (HA) was investigated for applications such as dentistry, regenerative medicine, cell culture scaffolding, and bio-sensors. An amorphous HA film was first produced by pulsed laser deposition. After deposition, it was separated from a substrate as a free-standing sheet. Annealing was then performed to control the crystallinity of the sheet. It was found that conventional annealing in an electric oven was not suitable for HA sheets, because it led to curling and cracking. Since such problems were assumed to be caused by thermal stress, annealing was next carried out with the HA sheet enclosed in HA powder in the center of a metal capsule. This method allowed annealing to be successfully carried out without causing any curling or cracking. Uniform pieces with dimensions of 10 mm × 10 mm cut from a large HA sheet were annealed at temperatures of 200 to 800 ºC and then examined using X-ray diffraction. It was found that the intensity of the diffraction peaks associated with crystalline HA changed with annealing temperature, and that the strongest peaks were observed for the sample annealed at 500 ºC. These results indicate that the crystallinity of the HA sheet can be controlled using the proposed method.

CRYSTALLINE SrTiO3 THIN FILMS ON SILICON BY PULSED LASER DEPOSITION

2005 ◽  
Vol 19 (01n03) ◽  
pp. 533-535
Author(s):  
J. H. HAO ◽  
J. GAO
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Perovskite Oxide ◽  
Deposition Technique ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Silicon Materials

We have developed a process to grow SrTiO 3 ( STO ) thin films showing single (110) orientation directly on Si by means of pulsed laser deposition technique. The growth of STO films directly on Si has been described. The crystallinity of the grown STO films was characterized by X-ray diffraction analysis of θ-2θ scan and rocking curve. Our results may be of interest for better understanding of the growth based on the perovskite oxide thin films on silicon materials.

Epitaxial Pd-Doped LaFeO3 Films Grown on (100) SrTiO3 by Pulsed Laser Deposition

2014 ◽  
Vol 936 ◽  
pp. 282-286
Author(s):  
Ying Wen Duan
Keyword(s):  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Film Surface ◽  
Laser Deposition ◽  
Structural Quality ◽  
Deposition Technique ◽  
X Ray Diffraction ◽  
Orientation Relationships ◽  
X Ray ◽  
Transmission Electron

Single-crystalline, epitaxial LaFeO3 films with 5 at. % substitution of Pd on the Fe site are grown on (100) SrTiO3 substrate by pulsed-laser deposition technique. The epitaxial orientation relationships are (110)[001]LFPO||(100)[001]STO. X-ray diffraction and transmission electron microscopy reveal that the LFPO films have high structural quality and an atomically sharp LFPO/STO interface. After reduction treatments of as-grown LFPO films, very little Pd escaped the LFPO lattice onto the film surface, the formed Pd (100) particles are oriented epitaxially, and parallel to the LFPO films surface.

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