scholarly journals Texture Analysis in LD-MOCVD Processed Thin Film Giant Magnetoresistant (LaM)MnO3 Materials

2000 ◽  
Vol 34 (2-3) ◽  
pp. 65-74 ◽  
Author(s):  
H. Garmestani ◽  
X. Dong ◽  
L. Brandao ◽  
K. -H. Dahmen
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Film Growth ◽  
Lattice Mismatch ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
X Ray ◽  
Mismatch Strain ◽  
Pole Figures ◽  
Lattice Mismatch Strain

Thin films of La0.67M0.33MnO3 (M=Sr), LSMO were deposited on three different substrates of LAO, Sapphire, and Y-ZrO2 (YSZ) using metal–organic chemical vapor deposition methods. The effect of texture and orientation on the resistance (0 and 6T) and magnetoresistance (MR) of (LSMO) thin films on various substrates has been investigated. X-ray pole figures were measured using Philips X’Pert X-ray diffractometer equipped with the PopLa analysis package. A direct correlation was observed between the lattice mismatch strain and the structure of the thin film growth. LSMO/LAO seems to be the most perfect system for epitaxial growth due to the negligible lattice-mismatch (∼2%). The dominant orientation changes for the films deposited on LAO [100] and LAO [110] substrates while the transition temperature from ferromagnetic to paramagnetic state of the film on LAO [100] is 50 K higher than that of the film on LAO [100]. The MR data and TMI temperature were measured using standard 4-point resistivity devices and SQUID.

Microstructural characterization of YBa2Cu3O7-x thin films formed by metalorganic CVD

1991 ◽  
Vol 49 ◽  
pp. 1080-1081
Author(s):  
P. Lu ◽  
W. Huang ◽  
C.S. Chern ◽  
Y.Q. Li ◽  
J. Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Film Growth ◽  
Chemical Vapor ◽  
Microstructural Characterization ◽  
Ion Milling ◽  
Conventional Grinding

The YBa2Cu3O7-x thin films formed by metalorganic chemical vapor deposition(MOCVD) have been reported to have excellent superconducting properties including a sharp zero resistance transition temperature (Tc) of 89 K and a high critical current density of 2.3x106 A/cm2 or higher. The origin of the high critical current in the thin film compared to bulk materials is attributed to its structural properties such as orientation, grain boundaries and defects on the scale of the coherent length. In this report, we present microstructural aspects of the thin films deposited on the (100) LaAlO3 substrate, which process the highest critical current density.Details of the thin film growth process have been reported elsewhere. The thin films were examined in both planar and cross-section view by electron microscopy. TEM sample preparation was carried out using conventional grinding, dimpling and ion milling techniques. Special care was taken to avoid exposure of the thin films to water during the preparation processes.

scholarly journals MOCVD of Field Emission Phosphors using a Liquid Delivery System

1997 ◽  
Vol 495 ◽  
Author(s):  
T. S. Moss ◽  
B. F. Espinoza ◽  
K. V. Salazar ◽  
R. C. Dye
Keyword(s):  
Thin Film ◽  
Field Emission ◽  
Delivery System ◽  
High Surface ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
X Ray ◽  
Surface Areas ◽  
Field Emission Displays ◽  
Liquid Delivery

ABSTRACTThin film phosphors for field emission displays show the potential to overcome the life-limiting problems that traditional powders face because of their high surface areas. By depositing a fully dense thin film, the surface area can be dramatically reduced, while the electrical and thermal conductivity is increased. Metal organic chemical vapor deposition offers the ability to deposit high quality, dense films that are crystalline-as-deposited and at temperatures low enough to allow for inexpensive glass. Deposition has been produced from mixtures of Y(tmhd)3, TEOS, Tb(tmhd)3, and O2 using a liquid delivery system. Coatings were shown to be composed of Y, Si, and Tb by x-ray fluorescence, but x-ray diffraction did not show any crystallinity. Excitation using radioluminescence produced a peak in the visible green at approximately 540 nm, indicative of the excitation of Tb3+. The morphology of the deposition was smooth, with surface features on the order of one micron and below. Some limited microcracking was also observed in the morphology because of the thermal expansion mismatch.

Thin films for superconducting electronics: Precursor performance issues, deposition mechanisms, and superconducting phase formation-processing strategies in the growth of Tl2Ba2CaCu2O8 films by metal-organic chemical vapor deposition

1997 ◽  
Vol 12 (5) ◽  
pp. 1214-1236 ◽  
Author(s):  
Bruce J. Hinds ◽  
Richard J. McNeely ◽  
Daniel B. Studebaker ◽  
Tobin J. Marks ◽  
Timothy P. Hogan ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Pressure ◽  
Vapor Deposition ◽  
Film Growth ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Organic Chemical ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

Epitaxial Tl2Ba2CaCu2O8 thin films with excellent electrical transport characteristics are grown in a two-step process involving metal-organic chemical vapor deposition (MOCVD) of a BaCaCuO(F) thin film followed by a postanneal in the presence of Tl2O vapor. Vapor pressure characteristics of the recently developed liquid metal-organic precursors Ba(hfa)2 • mep (hfa = hexafluoroacetylacetonate, mep = methylethylpentaglyme), Ca(hfa)2 • tet (tet = tetraglyme), and the solid precursor Cu(dpm)2 (dpm = dipivaloylmethanate) are characterized by low pressure thermogravimetric analysis. Under typical film growth conditions, transport is shown to be diffusion limited. The transport rate of Ba(hfa)2 • mep is demonstrated to be stable for over 85 h at typical MOCVD temperatures (120 °C). In contrast, the vapor pressure stability of the commonly used Ba precursor, Ba(dpm)2, deteriorates rapidly at typical growth temperatures, and the decrease in vapor pressure is approximately exponential with a half-life of ∼9.4 h. These precursors are employed in a low pressure (5 Torr) horizontal, hot-wall, film growth reactor for growth of BaCaCuO(F) thin films on (110) LaAlO3 substrates. From the dependence of film deposition rate on substrate temperature and precursor partial pressure, the kinetics of deposition are shown to be mass-transport limited over the temperature range 350–650 °C at a 20 nm/min deposition rate. A ligand exchange process which yields volatile Cu(hfa)2 and Cu(hfa) (dpm) is also observed under film growth conditions. The MOCVD-derived BaCaCuO(F) films are postannealed in the presence of bulk Tl2Ba2CaCu2O8 at temperatures of 720–890 °C in flowing atmospheres ranging from 0–100% O2. The resulting Tl2Ba2CaCu2O8 films are shown to be epitaxial by x-ray diffraction and transmission electron microscopic (TEM) analysis with the c-axis normal to the substrate surface, with in-plane alignment, and with abrupt film-substrate interfaces. The best films exhibit a Tc = 105 K, transport-measured Jc= 1.2 × 105 A/cm2 at 77 K, and surface resistances as low as 0.4 mΩ (40 K, 10 GHz).

Effects of Substrate Temperature on the Properties of Silicon Oxide Films by PECVD

2012 ◽  
Vol 198-199 ◽  
pp. 28-31
Author(s):  
Chun Ya Li ◽  
Xi Feng Li ◽  
Long Long Chen ◽  
Ji Feng Shi ◽  
Jian Hua Zhang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electrical Properties ◽  
Photoelectron Spectroscopy ◽  
Deposition Temperature ◽  
Silicon Oxide ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
X Ray ◽  
Glass Substrates

Under different growth conditions, silicon Oxide (SiOx) thin films were deposited successfully on Si (100) substrates and glass substrates by plasma enhanced chemical vapor deposition (PECVD). The thickness, refractive index and growth rate of the thin films were tested by ellipsometer. The effects of deposition temperature on the structure and properties of SiOx films were studied using X ray diffraction (XRD), X ray photoelectron spectroscopy (XPS) and UV-Visible spectroscopy. The results show that the SiOx films were amorphous at different deposition temperature. The peaks of Si2p and O1s shifted to higher binding energy with temperature increasing. The SiOx films had high transmissivity at the range of 400-900nm. By analyzing the observation and data, the influence of deposition parameters on the electrical properties and interface characteristics of SiOx thin film prepared by PECVD is systematically discussed. At last, SiOx thin film with excellent electrical properties and good interface characteristic is prepared under the relatively optimum parameters.

Growth of Ferroelectric PbZrxTi1-xO3 (PZT) Thin Films by Liquid-Delivery Metalorganic Chemical Vapor Deposition

2005 ◽  
Vol 902 ◽  
Author(s):  
Serhiy Matichyn ◽  
Marco Lisker ◽  
Edmund P. Burte
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Main Role ◽  
Pzt Thin Films ◽  
X Ray ◽  
Pzt Films ◽  
Deposited Films

AbstractIn this study lead zirkonat titanate (PZT) thin films were deposited using direct liquid injection metal organic chemical vapor deposition (DLI-MOCVD).The chemical states and the stoichiometry of PZT-films were characterized using X-ray photoelectron spectroscopy (XPS). The crystal structure of the films was investigated by X-ray diffraction (XRD).The surface composition of the films was Pb : Zr : Ti = 1.05 : 0.52 : 0.48, which indicates that the deposited films had a stoichiometric PZT composition. 130 nm thick PZT films deposited on Ir showed <110> preferred orientation.The main role for formation of the perovsktive PZT films plays the content of the lead in the deposited films. Lead deficiency causes the formation of the pyrochlore phase with poor electrical properties. In films with a significant excess of lead a second PbO phase appeared that can be observed even with naked eyes. Negligible excess of lead can be reduced by post-deposition annealing at 500-600 °C.The Ir/PZT/Ir capacitor showed large values of the remanent polarisation of about 60μC/cm2 at an applied voltage of 3 V. So high value of the remanent polarisation can be induced by structural stress in the films. After ten switch impulses the values of the remanent polarisation have significantly decreased. This is probably due to a relaxation of crystal cells.

scholarly journals Nanoindentation of Chromium Oxide Possessing Superior Hardness among Atomic-Layer-Deposited Oxides

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 82
Author(s):  
Taivo Jõgiaas ◽  
Aivar Tarre ◽  
Hugo Mändar ◽  
Jekaterina Kozlova ◽  
Aile Tamm
Keyword(s):  
Thin Films ◽  
Chemical Vapor ◽  
Atomic Layer ◽  
Organic Chemical ◽  
X Ray ◽  
Layer Deposition ◽  
Ammonium Dichromate ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition ◽  
Deposition Substrate

Chromium (III) oxide is a technologically interesting material with attractive chemical, catalytic, magnetic and mechanical properties. It can be produced by different chemical and physical methods, for instance, by metal–organic chemical vapor deposition, thermal decomposition of chromium nitrate Cr(NO3)3 or ammonium dichromate (NH4)2Cr2O7, magnetron sputtering and atomic layer deposition. The latter method was used in the current work to deposit Cr2O3 thin films with thicknesses from 28 to 400 nm at deposition temperatures from 330 to 465 °C. The phase composition, crystallite size, hardness and modulus of elasticity were measured. The deposited Cr2O3 thin films had different structures from X-ray amorphous to crystalline α-Cr2O3 (eskolaite) structures. The averaged hardness of the films on SiO2 glass substrate varied from 12 to 22 GPa and the moduli were in the range of 76–180 GPa, as determined by nanoindentation. Lower values included some influence from a softer deposition substrate. The results indicate that Cr2O3 could be a promising material as a mechanically protective thin film applicable, for instance, in micro-electromechanical devices.

Electrodeposition of lithium phthalocyanine thin films: Part I. Structure and morphology

1999 ◽  
Vol 14 (5) ◽  
pp. 2162-2172 ◽  
Author(s):  
M. Brinkmann ◽  
S. Graff ◽  
C. Chaumont ◽  
J-J. André
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Indium Tin Oxide ◽  
Film Growth ◽  
Oxidation Potential ◽  
Thin Film Growth ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
X Ray ◽  
Film Synthesis

A new thin film synthesis route based on the electrochemical oxidation of PcLi2 and deposition of lithium phthalocyanine (PcLi) onto indium tin oxide (ITO) substrate is demonstrated. The effects on the thin film morphology of various parameters such as the electrolysis time, the nature of the solvent, and the oxidation potential are investigated. The thin film growth is studied via x-ray diffraction, potential step experiments, and ex situ scanning electron microscopy. Various morphologies of the x-form thin films are observed for different electrolysis times and solvents. Thin films grown in acetonitrile of thickness above 1 μm consist in unidirectionally oriented needle-shaped crystallites.

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