MOCVD Growth and Structure of PbTiO3 Thin Films

1993 ◽  
Vol 310 ◽  
Author(s):  
Y. Gao ◽  
G. Bai ◽  
K. L. Merkle ◽  
H. L. M. Chang ◽  
D. J. Lam
Keyword(s):  
Thin Films ◽  
Layer Structure ◽  
Single Layer ◽  
Bottom Layer ◽  
Epitaxial Films ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
Mocvd Growth ◽  
Transmission Electron ◽  
Oriented Layers

AbstractPbTiO3 thin films grown on (001)MgO and (110)MgO by MOCVD have been characterized by x-ray diffraction and transmission electron microscopy. The PbTiO3 films deposited on (001)MgO under the optimum conditions always show a bi-layer structure. The top layer of the films near the free surface is c-axis oriented with the orientation relationship (001)[100]PbTiO3∥(001)[100]MgO. The bottom layer of the films near the substrate is a-axis oriented with (100)[001]PbTiO3∥(001)[100]MgO. 90° domains were observed, but only in the caxis oriented layers. The thickness of the a-axis oriented layers near the substrate decreases with decreasing the cooling rate. PbTiO3 films deposited on (110) MgO, however, are single-layer, epitaxial films with (101)[001]PbTiO3∥(110)[001]MgO.

MOCVD Growth of Epitaxial SrTiO3 Thin Films on YBa2 Cu3O7−x/LaAlO3

1993 ◽  
Vol 335 ◽  
Author(s):  
S. Liang ◽  
C. Chern ◽  
Z. Q. Shi ◽  
Y. Lu ◽  
P. Lu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Ac Susceptibility ◽  
Superconducting Property ◽  
Growth Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mocvd Growth ◽  
Transmission Electron ◽  
Substrate Temperatures

AbstractStrontium titanate (SrTiO3) thin films have been epitaxially grown on YB2Cu3O7−x (YBCO)/LaAlO3 at substrate temperatures of 660 to 700°C. X-ray diffraction (XRD) results indicated that single crystalline SrTiO3 thin films were epitaxially grown on the substrate with <100> orientation perpendicular to the substrates. The compositions of the films with different growth conditions were examined by Rutherford backscattering spectroscopy (RBS) and energy dispersive x-ray spectroscopy (EDX). The ratio of Sr/Ti is in the range of 0.9 to 1.1 for the films with a thickness of 1000–2000Å. The surface morphology of the films and the interfaces of the SrTiO3/YBCO structure were examined by scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). Very smooth surface and sharp interface were observed. The superconducting property of the YBCO layer, as measured by ac susceptibility, did not degrade after growth of SrTiO3 film. The dielectric constant as high as 320 was obtained at 100KHz. The leakage current density is less than 1×10−6A/cm2 at 3V operation.

Composition and Growth-Temperature Effect on the Microstructure of Epitaxial La1−x Srx MnO3 (x = 0, 0.2) Thin Films on (001) LaAlO3

2003 ◽  
Vol 18 (11) ◽  
pp. 2556-2561 ◽  
Author(s):  
J.C. Jiang ◽  
E.I. Meletis ◽  
K.I. Gnanasekar
Keyword(s):  
Thin Films ◽  
Size Distribution ◽  
Cross Section ◽  
Growth Temperature ◽  
Single Layer ◽  
Epitaxial Films ◽  
Narrow Size Distribution ◽  
Perovskite Layer ◽  
Plan View ◽  
Transmission Electron

La0.8Sr0.2MnO3 (LSMO) and LaMnO3 (LMO) thin films epitaxially grown on (001) LaAlO3 substrate at 700 and 800°C were studied using cross-section and plan-view transmission electron microscopy. In both LSMO and LMO films deposited at 700°C, a two-layered structure was observed: a continuous cubic perovskite layer epitaxially grown on the substrate followed by epitaxially grown orthorhombic column nanostructures. The orthogonal nano columns in LSMO were very well defined with a narrow size distribution. The LMO films exhibited a somewhat distorted orthogonal shape for the nanostructured columns and a wider size distribution. LSMO and LMO epitaxial films deposited at 800°C consisted of only a continuous single layer of cubic perovskite. These results reveal that formation of epitaxial column nanostructures in the La1-xSrxMnO3 thin films strongly depends on the growth temperature. Sr substitution on La sites in La1-xSrxMnO3 can improve uniformity of column size distribution and perfection of the orthogonal shape of nano columns.

Adjustment of Membrane Stress Using Aluminum Oxide and Silicon Dioxide Multi Layer Structure

2000 ◽  
Vol 657 ◽  
Author(s):  
Ryuichi Kubo ◽  
Yukio Yoshino ◽  
Kazuhiro Inoue ◽  
Takahiro Makino ◽  
Seiichi Arai
Keyword(s):  
Thin Films ◽  
Aluminum Oxide ◽  
Internal Stress ◽  
Layer Structure ◽  
Target Material ◽  
Rf Magnetron Sputtering ◽  
Electron Beam Evaporation ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
Total Stress

ABSTRACTRelaxation of internal stress for micro-electromechanical systems (MEMS) using SiO2 / Al2O3 / SiO2 membrane has been studied. The aluminum oxide thin films were formed by electron beam evaporation at room temperature. No peaks were observed in the X-ray diffraction pattern of the films. The ratio of Al and O in aluminum oxide was stoichiometric compared with Al2O3 target material. The internal stress was tensile at about 300-400 MPa. Bottom SiO2 thin film was formed by thermal oxidation and the top one by RF magnetron sputtering method. The internal stress of thermally oxidized SiO2 film was compressive at about 440 MPa, while that of the films deposited by sputtering, was compressive at about 100 MPa. The ratio of Si and O in each SiO2 thin films remained stoichiometric. The total stress of the membrane was controlled by optimizing the thickness of each film for relaxing the total stress of the membrane. The total stress of the membrane became almost zero under optimum conditions of SiO2 and Al2O3 films.

Epitaxy and texture analysis of Bi-Sr-Ca-Cu-O thin films on (100) MgO using Transmission Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 68-69
Author(s):  
J. T. Sizemore ◽  
D. G. Schlom ◽  
Z. J. Chen ◽  
J. N. Eckstein ◽  
I. Bozovic ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Critical Currents ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Cell Axis ◽  
Transmission Electron ◽  
Synthesis Procedure

Investigators observe large critical currents for superconducting thin films deposited epitaxially on single crystal substrates. The orientation of these films is often characterized by specifying the unit cell axis that is perpendicular to the substrate. This omits specifying the orientation of the other unit cell axes and grain boundary angles between grains of the thin film. Misorientation between grains of YBa2Cu3O7−δ decreases the critical current, even in those films that are c axis oriented. We presume that these results are similar for bismuth based superconductors and report the epitaxial orientations and textures observed in such films.Thin films of nominally Bi2Sr2CaCu2Ox were deposited on MgO using molecular beam epitaxy (MBE). These films were in situ grown (during growth oxygen was incorporated and the films were not oxygen post-annealed) and shuttering was used to encourage c axis growth. Other papers report the details of the synthesis procedure. The films were characterized using x-ray diffraction (XRD) and transmission electron microscopy (TEM).

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.

Physical Properties Of Single-Phase Skutterudite Thin-Films (CoSb3 and IrSb3)

1998 ◽  
Vol 545 ◽  
Author(s):  
J. C. Caylor ◽  
A. M. Stacy ◽  
T. Sands ◽  
R. Gronsky
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Growth Parameters ◽  
X Ray Diffraction ◽  
Adhesion Properties ◽  
Rutherford Back Scattering ◽  
Phonon Component ◽  
Transmission Electron ◽  
Structure Morphology ◽  
High Vapor

AbstractBulk skutterudite phases based on the CoAs3 structure have yielded compositions with a high thermoelectric figure-of-merit (“ZT”) through the use of doping and substitutional alloying. It is postulated that further enhancements in ZT may be attained in artificially structured skutterudites by engineering the microstructure to enhance carrier mobility while suppressing the phonon component of the thermal conductivity. In this work the growth and properties of singlephase CoSb3 and IrSb3 skutterudite thin films are reported. The films are synthesized by pulsed laser deposition (PLD) where the crystallinity can be controlled by the deposition temperature. Powder X-ray diffraction (PXRD), Transmission electron microscopy (TEM) and Rutherford- Back Scattering (RBS) were used to probe phase, structure, morphology and stoichiometry of the films as functions of growth parameters and substrate type. A substrate temperature of 250°C was found to be optimal for the deposition of the skutterudites from stoichiometric targets. Above this temperature the film is depleted of antimony due to its high vapor pressure eventually reaching a composition where the skutterudite structure is no longer stable. However, when films are grown from antimony-rich targets the substrate temperature can be increased to at least 350°C while maintaining the skutterudite phase. In addition, adhesion properties of the films are explored in terms of the growth mode and substrate interaction. Finally, preliminary room temperature electrical and thermal measurements are reported.

Polyaniline/SnO2 Nanocomposite Sensor for NO2 Gas Sensing at Low Operating Temperature

2015 ◽  
Vol 14 (04) ◽  
pp. 1550011 ◽  
Author(s):  
A. Sharma ◽  
M. Tomar ◽  
V. Gupta ◽  
A. Badola ◽  
N. Goswami
Keyword(s):  
Thin Films ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
Sensing Properties ◽  
Response Recovery ◽  
Transmission Electron ◽  
Gas Sensing Properties

In this paper gas sensing properties of 0.5–3% polyaniline (PAni) doped SnO 2 thin films sensors prepared by chemical route have been studied towards the trace level detection of NO 2 gas. The structural, optical and surface morphological properties of the PAni doped SnO 2 thin films were investigated by performing X-ray diffraction (XRD), Transmission electron microscopy (TEM) and Raman spectroscopy measurements. A good correlation has been identified between the microstructural and gas sensing properties of these prepared sensors. Out of these films, 1% PAni doped SnO 2 sensor showed high sensitivity towards NO 2 gas along with a sensitivity of 3.01 × 102 at 40°C for 10 ppm of gas. On exposure to NO 2 gas, resistance of all sensors increased to a large extent, even greater than three orders of magnitude. These changes in resistance upon removal of NO 2 gas are found to be reversible in nature and the prepared composite film sensors showed good sensitivity with relatively faster response/recovery speeds.

DIRECT GROWTH OF EPITAXIAL La0.67Ca0.33MnO3 - δ THIN FILMS

2002 ◽  
Vol 09 (05n06) ◽  
pp. 1611-1615 ◽  
Author(s):  
G. CAMPILLO ◽  
L. F. CASTRO ◽  
P. VIVAS ◽  
E. BACA ◽  
P. PRIETO ◽  
...  
Keyword(s):  
Thin Films ◽  
Substrate Surface ◽  
Electrical Characterization ◽  
Annealing Treatment ◽  
Pure Oxygen ◽  
X Ray Diffraction ◽  
Atomic Force ◽  
Transmission Electron ◽  
Afm Analysis ◽  
Direct Growth

La 0.67 Ca 0.33 MnO 3 - δ thin films were deposited using a high-pressure dc-sputtering process. Pure oxygen at a pressure of 3.8 mbar was used as sputtering gas. The films were grown on (001) LaAlO 3 and (001) SrTiO 3 substrates at heater temperature of 850° without any annealing treatment. The formation of highly a-axis-oriented films with sharp interface with substrate surface is demonstrated by X-ray diffraction, transmission electron microscope (TEM), and atomic force microscope (AFM) analysis. Electrical characterization revealed a metal–insulator transition at T MI = 276 K, and magnetic characterization showed good magnetic properties with a PM–FM transition at TC ≈ 262 K.

Microstructure of SrTiO3 Thin Films as Single Layer and Incorporated in Yba2Cu3O7-x/SrTiO3 Multilayers

1995 ◽  
Vol 401 ◽  
Author(s):  
L. Ryen ◽  
E. Olssoni ◽  
L. D. Madsen ◽  
C. N. L. Johnson ◽  
X. Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Lattice Mismatch ◽  
Single Layer ◽  
Transmission Electron ◽  
Tilt Boundaries ◽  
Interfacial Dislocations ◽  
The Individual ◽  
Film Substrate

AbstractEpitaxial single layer (001) SrTiO3 films and an epitaxial Yba2Cu3O7-x/SrTiO3 multilayer were dc and rf sputtered on (110)rhombohedral LaAIO3 substrates. The microstructure of the films was characterised using transmission electron microscopy. The single layer SrTiO3 films exhibited different columnar morphologies. The column boundaries were due to the lattice mismatch between film and substrate. The boundaries were associated with interfacial dislocations at the film/substrate interface, where the dislocations relaxed the strain in the a, b plane. The columns consisted of individual subgrains. These subgrains were misoriented with respect to each other, with different in-plane orientations and different tilts of the (001) planes. The subgrain boundaries were antiphase or tilt boundaries.The individual layers of the Yba2Cu3O7-x/SrTiO3 multilayer were relatively uniform. A distortion of the SrTiO3 unit cell of 0.9% in the ‘001’ direction and a Sr/Ti ratio of 0.62±0.04 was observed, both in correspondence with the single layer SrTiO3 films. Areas with different tilt of the (001)-planes were also present, within each individual SrTiO3 layer.

Classification of the Modes of Dissociation in Immiscible Cu-Alloy Thin Films

1999 ◽  
Vol 564 ◽  
Author(s):  
K. Barmak ◽  
G. A. Lucadamo ◽  
C. Cabral ◽  
C. Lavoie ◽  
J. M. E. Harper
Keyword(s):  
Thin Films ◽  
Driving Forces ◽  
Texture Evolution ◽  
Substantial Reduction ◽  
Alloying Elements ◽  
X Ray Diffraction ◽  
Cu Alloy ◽  
Transmission Electron ◽  
Evolution Of Microstructure

AbstractWe have found the dissociation behavior of immiscible Cu-alloy thin films to fall into three broad categories that correlate most closely with the form of the Cu-rich end of the binary alloy phase diagrams. The motivation for these studies was to use the energy released by the dissociation of an immiscible alloy, in addition to other driving forces commonly found in thin films and lines, to promote grain growth and texture evolution. In this work, the dissociation behavior of eight dilute (3.3 ± 0.5 at% solute) binary Cu-systems was investigated, with five alloying elements selected from group VB and VIB, two from group VillA, and one from group 1B. These alloying elements are respectively V, Nb, Ta, Cr, Mo, Fe, Ru and Ag. Several experimental techniques, including in situ resistance and stress measurements as well as in situ synchrotron x-ray diffraction, were used to follow the progress of solute precipitation in approximately 500 nm thick films. In addition, transmission electron microscopy was used to investigate the evolution of microstructure of Cu(Ta) and Cu(Ag). For all eight alloys, dissociation occurred upon heating, with the rejection of solute and evolution of microstructure and texture often occurring in multiple steps that range over several hundred degrees between approximately 100 and 900°C. However, in most cases, substantial reduction in resistivity of the films took place at temperatures of interest to metallization schemes, namely below 400°C.

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