Effect of Dopants on the Band Structure of Barium Strontium Titanate Thin Films

2005 ◽  
Vol 872 ◽  
Author(s):  
Yuebing Zheng ◽  
Shijie Wang ◽  
Cheng Hon A. Huan
Keyword(s):  
Crystal Structure ◽  
Thin Films ◽  
Band Structure ◽  
Dopant Concentration ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Barium Strontium ◽  
Transmission Electron

AbstractThe effect of dopants on the band structure and crystal structure of Ba0.5Sr0.5TiO3thin films on (100) LaAlO3 substrates has been investigated. The dopants include Ti, Mg and Al. The band-gap energies of the thin films were determined from the transmission spectra measured by UVVIS spectrophotometer and increased with the increase of dopant concentration regardless of the type of dopants. The crystal structure was studied by using transmission electron microscopy, atomic force microscopy, x-ray diffraction and micro-Raman spectroscopy. The relation between band structure and crystal structure was discussed.

Epitaxial BaTiO3 Thin Films on Different Substrates for Optical Waveguide Applications

1999 ◽  
Vol 597 ◽  
Author(s):  
M. Siegert ◽  
Judit G. Lisoni ◽  
C. H. Lei ◽  
A. Eckau ◽  
W. Zander ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Waveguides ◽  
Rutherford Backscattering Spectrometry ◽  
Optical Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Ion Channeling ◽  
Atomic Force ◽  
Transmission Electron

AbstractIn the process of developing thin film electro-optical waveguides we investigated the influence of different substrates on the optical and structural properties of epitaxial BaTiO3 thin films. These films are grown by on-axis pulsed laser deposition (PLD) on MgO(100), MgAl2O4(100), SrTiO3(100) and MgO buffered A12O3(1102) substrates. The waveguide losses and the refractive indices were measured with a prism coupling setup. The optical data are correlated to the results of Rutherford backscattering spectrometry/ion channeling (RBS/C). X-ray diffraction (XRD), atomic force microscopy (AFM) and transmission electron microscopy (TEM). BaTiO3 films on MgO(100) substrates show planar waveguide losses of 3 dB/cm and ridge waveguide losses of 5 dB/cm at a wavelength of 633 nm.

Epitaxial growth of PbTiO3 thin films on (001) SrTiO3 from solution precursors

1995 ◽  
Vol 10 (3) ◽  
pp. 680-691 ◽  
Author(s):  
Andreas Seifert ◽  
Fred F. Lange ◽  
James S. Speck
Keyword(s):  
Thin Films ◽  
Stable Phase ◽  
X Ray Diffraction ◽  
Amorphous Precursor ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Heat Treated ◽  
Film Substrate

A mixed alkoxide liquid precursor was used to form epitaxial PbTiO3 thin films by spin-coating on cubic (001) SrTiO3 substrates. The films were heat-treated at temperatures between 380 °C/1 h and 800 °C/1 h. X-ray diffraction, atomic force microscopy, scanning and transmission electron microscopy were used to characterize the microstructure of the films and to evaluate the epitaxial phenomena. At ∼400 °C/1 h, a polycrystalline, metastable Pb-Ti fluorite crystallizes from the pyrolyzed amorphous precursor. At slightly higher temperatures (∼420 °C/1 h), the thermodynamically stable phase with the perovskite structure epitaxially nucleates at the film/substrate interface. A small number of epitaxial grains grow through the film toward the surface and consume the nanocrystalline fluorite grains. Coarsening of the perovskite grains leads to a reduction in mosaic spread during further heating. Pores, which concurrently coarsen with grain growth, produce a pitted surface as they disappear from within the film. At 800 °C/1 ha dense epitaxial PbTiO3 film with a smooth surface is observed. Parameters governing the formation of a- and c-domains are discussed as well as the small tilts of the domain axes away from the substrate normal.

UNDERLAYER ROUGHNESS INFLUENCE ON THE PROPERTIES OF Ag THIN FILM

2008 ◽  
Vol 15 (06) ◽  
pp. 787-791
Author(s):  
PEI ZHAO ◽  
RENG WANG ◽  
DINGQUAN LIU ◽  
FENGSHAN ZHANG ◽  
WEITAO SU ◽  
...  
Keyword(s):  
Thin Film ◽  
Crystal Structure ◽  
Thin Films ◽  
Optical Constants ◽  
Reflectance Spectrum ◽  
Optical And Electrical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force

The effects of the roughness of ZnS underlayer on the microstructure, optical, and electrical properties of nanometer Ag thin film have been investigated in this paper. Nanometer Ag thin films in glass/ ZnS /7.5 nm Ag /30 nm ZnS stacks have been deposited and analyzed. In the stacks, the underlayers of ZnS have been sputtered with various thicknesses to generate various surface roughnesses. The X-ray diffraction (XRD) has been used to study the crystal structure of Ag films. The surface topography and the roughness of ZnS underlayer have been analyzed by atomic force microscopy. The sheet resistant will become larger as the increasing of the roughness. The optical constants can be derived by fitting the transmission and reflectance spectrum. From optical constants comparison of Ag films, with the surface of the stack becoming rougher, it was found that the refractive index will increase but the extinction coefficient will decrease.

Structural and Surface Morphology Changes in CuInSe2 Thin Films as a Function of Cu/In Ratio

1996 ◽  
Vol 441 ◽  
Author(s):  
P. Fons ◽  
S. Niki ◽  
A. Yamada ◽  
D. J. Tweet
Keyword(s):  
Thin Films ◽  
Molecular Beam ◽  
Morphological Changes ◽  
Epitaxial Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
The Ideal

AbstractDue to its high near bandedge absorption, CuInSe2 is considered to be one of the most promising solar cell materials. As CuInSe2 films are usually grown by metastable processes, the Cu/In ratio often deviates from the ideal ratio of unity. To investigate the structural and morphological changes induced by such stoichiometric variations we have grown a series of epitaxial CuInSe2 epitaxial thin films with varying Cu/In ratios by molecular beam epitaxy on GaAs(001) substrates from elemental sources at a growth temperature of 450° C. Overall structural, microstructural and surface morphological changes were observed by X-ray diffraction, transmission electron microscopy, and atomic force microscopy, respectively. It was observed that as films deviated from stoichiometry, twinning occurred preferentially on the anion {1 · 1 · 2} planes.

Formation of the YBa2Cu2NbOy phase in thin films

2009 ◽  
Vol 24 (1) ◽  
pp. 212-216
Author(s):  
Srinivas Sathiraju ◽  
Paul N. Barnes ◽  
Robert A. Wheeler
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Photoelectron Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Micro Raman Spectroscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
New Phase

We report the systematic substitution of Nb at the Cu1 site of YBa2Cu3Oy in thin films to form a new phase of YBa2Cu2NbO8. These films were deposited on SrTiO3(100) crystals using pulsed laser deposition and deposited at an optimal temperature of 850 °C. Films were characterized using x-ray diffraction (XRD), atomic force microscopy, x-ray photoelectron spectroscopy (XPS), micro-Raman spectroscopy, and transmission electron microscopy. XRD of these films indicate c-axis oriented YBa2Cu2NbOy formation. XPS and micro-Raman spectroscopy analysis suggests Cu exists in the +2 state.

Nanocrystalline Solutions as Precursors to The Spray Deposition of Cdte Thin Films

1995 ◽  
Vol 382 ◽  
Author(s):  
Martin Pehnt ◽  
Douglas L. Schulz ◽  
Calvin J. Curtis ◽  
Helio R. Moutinho ◽  
Amy Swartzlander ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Grain Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Cdte Nanoparticles ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Cdte Thin Films

ABSTRACTIn this article we report the first nanoparticle-derived route to smooth, dense, phase-pure CdTe thin films. Capped CdTe nanoparticles were prepared by injection of a mixture of Cd(CH3)2, (n-C8H17)3 PTe and (n-C8H17)3P into (n-C8H17)3PO at elevated temperatures. The resultant nanoparticles 32-45 Å in diameter were characterized by x-ray diffraction, UV-Vis spectroscopy, transmission electron microscopy, thermogravimetric analysis and energy dispersive x-ray spectroscopy. CdTe thin film deposition was accomplished by dissolving CdTe nanoparticles in butanol and then spraying the solution onto SnO2-coated glass substrates at variable susceptor temperatures. Smooth and dense CdTe thin films were obtained using growth temperatures approximately 200 °C less than conventional spray pyrolysis approaches. CdTe films were characterized by x-ray diffraction, UV-Vis spectroscopy, atomic force microscopy, and Auger electron spectroscopy. An increase in crystallinity and average grain size as determined by x-ray diffraction was noted as growth temperature was increased from 240 to 300 °C. This temperature dependence of film grain size was further confirmed by atomic force microscopy with no remnant nanocrystalline morphological features detected. UV-Vis characterization of the CdTe thin films revealed a gradual decrease of the band gap (i.e., elimination of nanocrystalline CdTe phase) as the growth temperature was increased with bulk CdTe optical properties observed for films grown at 300 °C.

scholarly journals Influence of the growth parameters of TiO2 thin films deposited by the MOCVD method

Cerâmica ◽  
2002 ◽  
Vol 48 (305) ◽  
pp. 38-42 ◽  
Author(s):  
M. I. B. Bernardi ◽  
E. J. H. Lee ◽  
P. N. Lisboa-Filho ◽  
E. R. Leite ◽  
E. Longo ◽  
...  
Keyword(s):  
Thin Films ◽  
Growth Parameters ◽  
Structural Characteristics ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Tio2 Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Deposition Parameters

The synthesis of TiO2 thin films was carried out by the Organometallic Chemical Vapor Deposition (MOCVD) method. The influence of deposition parameters used during growth on the final structural characteristics was studied. A combination of the following experimental parameters was studied: temperature of the organometallic bath, deposition time, and temperature and substrate type. The high influence of those parameters on the final thin film microstructure was analyzed by scanning electron microscopy with electron dispersive X-ray spectroscopy, atomic force microscopy and X-ray diffraction.

(G03 Best Paper Award Winner) Analysis of Sn Behavior During Ni/GeSn Solid-State Reaction by Correlated X-ray Diffraction, Atomic Force Microscopy, and Ex-situ/In-situ Transmission Electron Microscopy

2020 ◽  
Vol MA2020-02 (24) ◽  
pp. 1750-1750
Author(s):  
Andrea Quintero Colmenares ◽  
Patrice Gergaud ◽  
Jean-Michel Hartmann ◽  
Vincent Delaye ◽  
Nicolas Bernier ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Ex Situ ◽  
Paper Award ◽  
X Ray Diffraction ◽  
Award Winner ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

Evaluation of the Strain Field Inside and Around Growth Islands by Means of X-Ray Diffuse Scattering

1999 ◽  
Vol 583 ◽  
Author(s):  
Martin Schmidbauer ◽  
Thomas Wiebach ◽  
Helmut Raidt ◽  
Peter Schäfer ◽  
Michael hanke ◽  
...  
Keyword(s):  
Strain Field ◽  
Reciprocal Space ◽  
X Ray Diffraction ◽  
Abrupt Increase ◽  
X Ray ◽  
Force Microscopy ◽  
Self Organized ◽  
Atomic Force ◽  
Transmission Electron ◽  
Highly Strained

AbstractThe strain distribution inside and in the vicinity of coherently strained self-organized islands has been investigated by high-resolution x-ray diffraction (HRXRD). Finite element method (FEM) calculations were carried out in order to calculate the strain field, which was then used to simulate x-ray reciprocal space maps on the basis of kinematical scattering theory. For Si0 75Ge0.25 islands an abrupt increase in the Ge-concentration at about one third of the island height has been found. This behavior can be attributed to different nucleation stages during growth. Highly strained buried CdSe quantum dots (QDs) strongly influence the surrounding ZnSe matrix. From reciprocal space maps and FEM simulations we were able to estimate the shape and size of the islands. The results are in agreement with transmission electron microscopy (TEM) and UHV atomic force microscopy (AFM) data.

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