Growth temperature dependence of crystal symmetry in Nb-doped BaTiO3 thin films

2013 ◽  
Vol 03 (02) ◽  
pp. 1350009 ◽  
Author(s):  
Young Heon Kim ◽  
Xubing Lu ◽  
Marco Diegel ◽  
Roland Mattheis ◽  
Dietrich Hesse ◽  
...  
Keyword(s):  
Thin Films ◽  
Growth Temperature ◽  
Defect Density ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Threading Defects ◽  
Tetragonal Phase Transition

Growth temperature effects on the microstructure of Nb -doped BaTiO 3 thin films of the composition BaTi 0.98 Nb 0.02 O 3 are studied using X-ray diffraction and transmission electron microscopy (TEM). Reciprocal space maps and electron diffraction patterns show that the a-axis lattice parameter increases and the c-axis parameter decreases with increasing growth temperature, indicating a decrease of tetragonality. Bright-field TEM images show low and high densities of threading defects in films grown at low and high temperatures, respectively. The observations are discussed in terms of a hindering of the cubic-to-tetragonal phase transition by a high defect density and a high unit cell volume.

Textured Superconducting Thin Films of Bismuth Cuprate by Laser Ablation Method

1989 ◽  
Vol 169 ◽  
Author(s):  
Ashok Kumar ◽  
L. Ganapathi ◽  
J. Narayan
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Bulk Material ◽  
Lattice Parameter ◽  
Superconducting Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Laser Ablation Method ◽  
Zero Resistance ◽  
Diffraction Patterns

AbstractWe have prepared highly textured superconducting thin films from Bi1.5pb0.5Ca3Sr2Cu4Ox (2324) on (100) YS-ZrO2 (Yttria stabilized zirconia) and Bi1.5Pb0.5Ca2Sr2Cu3°x (2223) on LaAlC-3 (100) and MgO (100) substrates at 650°C by pulsed laser ablation method.These films showed 2212 type of phase of the (BiPb)2(Ca,Sr)n+1CunO2n+4+5 family with onset transition temperature ( Tc ) ~ 110 K, confirming our earlier observations of 110 K superconductivity in a n = 2 bulk material. Thin films deposited from 2324 bulk target on YS-Z1O2 showed zero resistance temperature (Tco ) of 68 K but post annealing for one hour at 400°C in oxygen improved Tco from 68 K to 82 K. Thin films from 2223 target on LaAlO3 ( 100 ) and MgO ( 100 ) exhibited a Tco of 65 K and 74 K respectively while onset remained the same at 110 K. Further annealing at 400°C for one hour in oxygen did not show any improvement in Tco. X-ray diffraction (XRD), scanning electron microscopy (SEM) and Rutherford backscattering (RBS) channeling studies were performed on these films for correlation between crystal structure, microstructure and superconducting properties. X-ray diffraction patterns indicated 2212 type phase with a= 5.39 Å and c=30.76 Å; preferential orientation of c-axis perpendicular to the substrate was observed. The lattice parameter and x-ray diffraction patterns were found to be invariant with annealing treatments.

Tem Investigation of Growth Temperature Dependence in Pulsed-Laser Ablated PLZT Films for Pyroelectric Applications

1999 ◽  
Vol 596 ◽  
Author(s):  
R. N. Jacobs ◽  
R. P. Godfrey ◽  
W. L. Sarney ◽  
C. W. Tipton ◽  
L. Salamanca-Riba
Keyword(s):  
Growth Temperature ◽  
Deposition Temperature ◽  
Structural Characteristics ◽  
Pulsed Laser ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Domain Orientation ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Patterns

AbstractTransmission electron microscopy is used to examine the structural characteristics of Pb0.9La0.1Zr0.2Ti0.8O3 (PLZT) films grown directly on single crystal LaAlO3 (LAO) substrates. In particular, the domain orientation and film epitaxial quality as a function of substrate deposition temperature are obtained in the range 500–650°C and compared to x-ray diffraction results. High-resolution cross sectional images and electron diffraction patterns confirm that domain orientation and overall epitaxial quality can be optimized with growth temperature. In addition, these results show a direct correlation with pyroelectric measurements obtained for capacitor structures incorporating La1−xSrxCoO3 (LSCO) top and bottom electrodes.

Palladium Nanowire Thin Films via Template Growth

2003 ◽  
Vol 775 ◽  
Author(s):  
Donghai Wang ◽  
David T. Johnson ◽  
Byron F. McCaughey ◽  
J. Eric Hampsey ◽  
Jibao He ◽  
...  
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Conductive Substrate ◽  
Palladium Nanowires ◽  
Efficient Route ◽  
Silica Thin Film

AbstractPalladium nanowires have been electrodeposited into mesoporous silica thin film templates. Palladium continually grows and fills silica mesopores starting from a bottom conductive substrate, providing a ready and efficient route to fabricate a macroscopic palladium nanowire thin films for potentially use in fuel cells, electrodes, sensors, and other applications. X-ray diffraction (XRD) and transmission electron microscopy (TEM) indicate it is possible to create different nanowire morphology such as bundles and swirling mesostructure based on the template pore structure.

Cetyltrimethylammonium bromide- and ethylene glycol-assisted preparation of mono-dispersed indium oxide nanoparticles using hydrothermal method

2014 ◽  
Vol 68 (8) ◽  
Author(s):  
Selvakumar Dhanasingh ◽  
Dharmaraj Nallasamy ◽  
Saravanan Padmanapan ◽  
Vinod Padaki
Keyword(s):  
Ethylene Glycol ◽  
Hydrothermal Method ◽  
Indium Oxide ◽  
Cetyltrimethylammonium Bromide ◽  
Oxide Nanoparticles ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Patterns

AbstractThe influence of cetyltrimethylammonium bromide and ethylene glycol on the size and dispersion of indium oxide nanoparticles prepared under hydrothermal conditions was investigated. The precursor compound, indium hydroxide, obtained by the hydrothermal method in the absence as well as the presence of cetyltrimethylammonium bromide, was converted to indium oxide by sintering at 400°C. The formation of nanoscale indium oxide upon sintering was ascertained by the characteristic infrared adsorption bands and X-ray diffraction patterns of indium oxide. Transmission electron microscopy and band gap values confirmed that the cetyltrimethylammonium bromide facilitated the formation of indium oxide nanoparticles smaller in size and narrower in distribution than those prepared without the assistance of cetyltrimethylammonium bromide.

Determining the C60 molecular arrangement in thin films by means of X-ray diffraction

2011 ◽  
Vol 44 (5) ◽  
pp. 983-990 ◽  
Author(s):  
Chris Elschner ◽  
Alexandr A. Levin ◽  
Lutz Wilde ◽  
Jörg Grenzer ◽  
Christian Schroer ◽  
...  
Keyword(s):  
Thin Films ◽  
Structural Information ◽  
Grazing Incidence ◽  
Test Material ◽  
C60 Fullerene ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molecular Arrangement ◽  
Diffraction Patterns

The electrical and optical properties of molecular thin films are widely used, for instance in organic electronics, and depend strongly on the molecular arrangement of the organic layers. It is shown here how atomic structural information can be obtained from molecular films without further knowledge of the single-crystal structure. C60 fullerene was chosen as a representative test material. A 250 nm C60 film was investigated by grazing-incidence X-ray diffraction and the data compared with a Bragg–Brentano X-ray diffraction measurement of the corresponding C60 powder. The diffraction patterns of both powder and film were used to calculate the pair distribution function (PDF), which allowed an investigation of the short-range order of the structures. With the help of the PDF, a structure model for the C60 molecular arrangement was determined for both C60 powder and thin film. The results agree very well with a classical whole-pattern fitting approach for the C60 diffraction patterns.

scholarly journals Elaboration of nitride thin films by reactive sputtering

2006 ◽  
Vol 59 (2) ◽  
pp. 225-232 ◽  
Author(s):  
Pierre Yves Jouan ◽  
Arnaud Tricoteaux ◽  
Nicolas Horny
Keyword(s):  
Thin Films ◽  
Compressive Stress ◽  
Bias Voltage ◽  
Substrate Surface ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
A Value ◽  
Dc Reactive Magnetron Sputtering ◽  
Nitrogen Contents

The aim of this paper is first a better understanding of DC reactive magnetron sputtering and its implications, such as the hysteresis effect and the process instability. In a second part, this article is devoted to an example of specific application: Aluminium Nitride. AlN thin films have been deposited by reactive triode sputtering. We have studied the effect of the nitrogen contents in the discharge and the RF bias voltage on the growth of AlN films on Si(100) deposited by triode sputtering. Stoichiometry and crystal orientation of AlN films have been characterized by means of Fourier-transform infrared spectroscopy, X-ray diffraction and secondary electron microscopy. Dense and transparent AlN layers were obtained at high deposition rates. These films have a (002) orientation whatever the nitrogen content in the discharge, but the best crystallised ones are obtained at low value (10%). A linear relationship was observed between the AlN lattice parameter "c" (perpendicular to the substrate surface) and the in-plane compressive stress. Applying an RF bias to the substrate leads to a (100) texture, and films become amorphous. Moreover, the film's compressive stress increases up to a value of 8GPa before decreasing slowly as the bias voltage increases.

Facile Refluxing Synthesis of Hydroxyapatite Nanoparticles

2015 ◽  
Vol 68 (8) ◽  
pp. 1293 ◽  
Author(s):  
Pakvipar Chaopanich ◽  
Punnama Siriphannon
Keyword(s):  
Crystallite Size ◽  
Reaction Times ◽  
Single Step ◽  
Hydroxyapatite Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Aqueous Mixture ◽  
Diffraction Patterns ◽  
Microscopy Images

Hydroxyapatite (HAp) nanoparticles were successfully synthesized from an aqueous mixture of Ca(NO3)2·4H2O and (NH4)2HPO4 by a facile single-step refluxing method using polystyrene sulfonate (PSS) as a template. The effects of reaction times, pH, and PSS concentration on the HAp formation were investigated. It was found that the crystalline HAp was obtained under all conditions after refluxing the precursors for 3 and 6 h. The longer refluxing time, the greater the crystallinity and the larger the crystallite size of the HAp nanoparticles. The HAp with poor crystallinity was obtained at pH 8.5; however, the well-crystallized HAp was obtained when reaction pH was increased to 9.5 and 10.5. In addition, the X-ray diffraction patterns revealed that the presence of PSS template caused the reduction of HAp crystallite size along the (002) plane from 52.6 nm of non-template HAp to 43.4 nm and 41.4 nm of HAp with 0.05 and 0.2 wt-% PSS template, respectively. Transmission electron microscopy images of the synthesized HAp revealed the rod-shaped crystals of all samples. The synthesized HAp nanoparticles were modified by l-aspartic acid (Asp) and l-arginine (Arg), having negative and positive charges, respectively. It was found that the zeta potential of HAp was significantly changed from +5.46 to –24.70 mV after modification with Asp, whereas it was +4.72 mV in the Arg-modified HAp. These results suggested that the negatively charged amino acid was preferentially adsorbed onto the synthesized HAp surface.

scholarly journals Effect of indium content on X- ray diffraction and optical constants of InxSe1-x thin films

2019 ◽  
Vol 14 (29) ◽  
pp. 55-72
Author(s):  
Bushra A. Hasan
Keyword(s):  
Thin Films ◽  
Optical Constants ◽  
Indium Content ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Dispersion Energy ◽  
X Ray ◽  
Evaporation Technique ◽  
High Indium Content ◽  
Diffraction Patterns

Alloys of InxSe1-x were prepared by quenching technique withdifferent In content (x=10, 20, 30, and 40). Thin films of these alloyswere prepared using thermal evaporation technique under vacuum of10-5 mbar on glass, at room temperature R.T with differentthicknesses (t=300, 500 and 700 nm). The X–ray diffractionmeasurement for bulk InxSe1-x showed that all alloys havepolycrystalline structures and the peaks for x=10 identical with Se,while for x=20, 30 and 40 were identical with the Se and InSestandard peaks. The diffraction patterns of InxSe1-x thin film showthat with low In content (x=10, and 20) samples have semicrystalline structure, The increase of indium content to x=30decreases degree of crystallinity and further increase of indiumcontent to x=40 leads to convert structure to amorphous. Increase ofthickness from 300 to 700nm increases degree of crystallinity for allindium content. Transmittance measurements were used to calculaterefractive index n and the extinction coefficient k using Swanepole’smethod. The optical constants such as refractive index (n), extinctioncoefficient (k) and dielectric constant (εr, εi) increases for low indiumcontent samples and decreases for high indium content samples,while increase of thickness increases optical constants for all xvalues. The oscillator energy E0, dispersion energy Ed, and otherparameters have been determined by Wemple - DiDomenico singleoscillator approach.

Structural and optical properties of Ba(Co1−xZnx)SiO4 (x = 0.2, 0.4, 0.6, 0.8)

2019 ◽  
Vol 34 (3) ◽  
pp. 242-250 ◽  
Author(s):  
J. Anike ◽  
R. Derbeshi ◽  
W. Wong-Ng ◽  
W. Liu ◽  
D. Windover ◽  
...  
Keyword(s):  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Powder Diffraction File ◽  
Visible Absorption ◽  
X Ray ◽  
Lattice Volume ◽  
Uv Visible ◽  
Diffraction Patterns ◽  
Pattern Determination ◽  
Bright Blue

Structural characterization and X-ray reference powder pattern determination have been conducted for the Co- and Zn-containing tridymite derivatives Ba(Co1−xZnx)SiO4 (x = 0.2, 0.4, 0.6, 0.8). The bright blue series of Ba(Co1−xZnx)SiO4 crystallized in the hexagonal P63 space group (No. 173), with Z = 6. While the lattice parameter “a” decreases from 9.126 (2) Å to 9.10374(6) Å from x = 0.2 to 0.8, the lattice parameter “c” increases from 8.69477(12) Å to 8.72200(10) Å, respectively. Apparently, despite the similarity of ionic sizes of Zn2+ and Co2+, these opposing trends are due to the framework tetrahedral tilting of (ZnCo)O4. The lattice volume, V, remains comparable between 626.27 Å3 and 626.017 (7) Å3 from x = 0 to x = 0.8. UV-visible absorption spectrum measurements indicate the band gap of these two materials to be ≈3.3 and ≈3.5 eV, respectively, therefore potential UV photocatalytic materials. Reference powder X-ray diffraction patterns of these compounds have been submitted to be included in the Powder Diffraction File (PDF).

Limitations to the use of Sb as a Surfactant During SiGe MBE

1998 ◽  
Vol 533 ◽  
Author(s):  
Glenn G. Jernigan ◽  
Conrad L. Silvestre ◽  
Mohammad Fatemi ◽  
Mark E. Twigg ◽  
Phillip E. Thompson
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Quantum Well ◽  
Photoelectron Spectroscopy ◽  
Surface Coverage ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Alloy Concentration

AbstractThe use of Sb as a surfactant in suppressing Ge segregation during SiGe alloy growth was investigated as a function of Sb surface coverage, Ge alloy concentration, and alloy thickness using xray photoelectron spectroscopy, x-ray diffraction, and transmission electron microscopy. Unlike previous studies where Sb was found to completely quench Ge segregation into a Si capping layer, we find that Sb can not completely prevent Ge segregation while Si and Ge are being co-deposited. This results in the production of a non-square quantum well with missing Ge at the beginning and extra Ge at the end of the alloy. We also found that Sb does not relieve strain in thin films but does result in compositional or strain variations within thick alloy layers.

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