Role of Oxygen Vacancies on the Ferroelectric Properties of Pzt Thin Films

1991 ◽  
Vol 243 ◽  
Author(s):  
Chi Kong Kwok ◽  
Seshu B. Desu
Keyword(s):  
Thin Films ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Vacancy Concentration ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Low Oxygen ◽  
Partial Pressures ◽  
Pzt Films

AbstractThe properties of ferroelectric thin films can be significantly influenced by the presence of point defects. The concentration of vacancies presented in these thin films is known to be one of the key parameters causing the degradation of these films when these films are subjected to polarization reversals.To study the effects of the vacancy concentration on the ferroelectric properties, sol gel PZT films and powders were annealed in different oxygen partial pressures. For the PZT films, the reduction of oxides to pure metals was not observed even with films annealed at 2×10−5 atmosphere of oxygen partial pressure. Samples annealed at low oxygen partial pressure (for instance, 10−3 and 2×10−5 atmosphere), which has more Pb and O2 depletions and consequently has more Pb and O2 vacancies, cannot be switched easily. The ratios of coercive field after and before fatigue increase as the defect concentrations of the annealed samples increase.

Tensile Properties and Creep Behavior of SiC-Based Fibers under Various Oxygen Partial Pressures

2005 ◽  
Vol 475-479 ◽  
pp. 1333-1336 ◽  
Author(s):  
Jan Ji Sha ◽  
J.S. Park ◽  
Tatsuya Hinoki ◽  
Akira Kohyama ◽  
J. Yu
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Tensile Properties ◽  
Creep Behavior ◽  
Elevated Temperatures ◽  
Low Oxygen ◽  
X Ray Diffraction ◽  
Sic Fibers ◽  
Partial Pressures ◽  
Ar Gas

Three kinds of atmospheres (air, highly-pure Ar and ultra highly-pure Ar gas) with different oxygen partial pressures were applied to investigate the tensile properties and creep behavior of SiC fibers such as Hi-NicalonTM and TyrannoTM-SA. These fibers were annealed and crept at elevated temperatures ranging from1273-1773 K in such environments. After annealing at 1773 K, the room temperature tensile strengths of SiC-based fibers decreased with decreasing the oxygen partial pressure and the near stoichiometric fiber TyrannoTM-SA shows excellent strength retention. At temperatures above the 1573 K, the creep resistance of SiC fibers evaluated by bending stress relaxation (BSR) method under high oxygen partial pressure was lower than that of in low oxygen partial pressure. The microstructural features on these fibers were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD).

In Situ Deposition of YBCO Thin Films by Sputtering under Low Oxygen Partial Pressure

1994 ◽  
Vol 33 (Part 2, No. 5B) ◽  
pp. L718-L721 ◽  
Author(s):  
Yong Ki Park ◽  
Keunseop Park ◽  
Soon-Gul Lee ◽  
Dong Chan Shin ◽  
Jong-Chul Park
Keyword(s):  
Thin Films ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Low Oxygen ◽  
Ybco Thin Films ◽  
In Situ Deposition

scholarly journals Process-Parameter-Dependent Structural, Electrical, and Optical Properties of Reactive Magnetron Sputtered Ag-Cu-O Films

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
P. Narayana Reddy ◽  
A. Sreedhar ◽  
M. Hari Prasad Reddy ◽  
S. Uthanna ◽  
J. F. Pierson
Keyword(s):  
Optical Properties ◽  
Substrate Temperature ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Rf Magnetron Sputtering ◽  
Low Oxygen ◽  
Electrical And Optical Properties ◽  
Partial Pressures ◽  
Effect Of Oxygen ◽  
Parameter Dependent

Silver-copper-oxide thin films were formed by RF magnetron sputtering technique using Ag80Cu20target at various oxygen partial pressures in the range 5 × 10−3–8 ×10−2 Pa and substrate temperatures in the range 303–523 K. The effect of oxygen partial pressure and substrate temperature on the structure and surface morphology and electrical and optical properties of the films were studied. The Ag-Cu-O films formed at room temperature (303 K) and at low oxygen partial pressure of 5 × 10−3 Pa were mixed phase of Ag2Cu2O3and Ag, while those deposited at 2 × 10−2 Pa were composed of Ag2Cu2O4and Ag2Cu2O3phases. The crystallinity of the films formed at oxygen partial pressure of 2 × 10−2Pa increased with the increase of substrate temperature from 303 to 423 K. Further increase of substrate temperature to 523 K, the films were decomposed in to Ag2O and Ag phases. The electrical resistivity of the films decreased from 0.8 Ωcm with the increase of substrate temperature from 303 to 473 K due to improvement in the crystallinity of the phase. The optical band gap of the Ag-Cu-O films increased from 1.47 to 1.83 eV with the increase of substrate temperature from 303 to 473 K.

Role of oxygen partial pressure and seed layer chemistry in flux mediated epitaxy of single phase multiferroic BiFeO3 thin films

2008 ◽  
Vol 93 (19) ◽  
pp. 192906 ◽  
Author(s):  
Varatharajan Anbusathaiah ◽  
Ching Jung Cheng ◽  
Sung Hwan Lim ◽  
Makoto Murakami ◽  
Lourdes G. Salamanca-Riba ◽  
...  
Keyword(s):  
Thin Films ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Seed Layer ◽  
Single Phase ◽  
Bifeo3 Thin Films ◽  
Multiferroic Bifeo3

Effect of Oxygen Partial Pressure on the Morphological Properties and the Photocatalytic Activities of Titania Thin Films on Unheated Substrates by Sputtering Deposition Method

2013 ◽  
Vol 770 ◽  
pp. 18-21 ◽  
Author(s):  
P. Pungboon Pansila ◽  
Nirun Witit-Anun ◽  
Surasing Chaiyakun
Keyword(s):  
Thin Films ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Anatase Phase ◽  
Rutile Phase ◽  
Morphological Properties ◽  
Low Oxygen ◽  
Working Pressure ◽  
Sputtering Deposition ◽  
Photocatalytic Activities

Titania (TiO2) thin films have been deposited using d.c. reactive unbalance magnetron sputtering on unheated substrate by various different oxygen partial pressures while working pressure and sputtering power were kept constant. A pure metallic titanium disk was used for sputtering target in atmospheric of the mixture gases between argon and oxygen. The X-ray diffraction (XRD) and atomic force microscopy (AFM) were used for characterization of characteristics structure and surface morphologies of the films, respectively. The optical transmission of the films were measured by spectrophotometer. The photocatalytic activities of the films were investigated from measurement of methylene blue degradation by using absorbance value after UV irradiation for 6 hr. The results show that the crystalline structures of the films showed the presence of single-anatase phase and mixed-anatase/rutile phase of TiO2 thin films. The surface morphology and photocatalytic activities of the films depend on oxygen partial pressure that grains size, surface roughness and thickness of the films were deceased when increasing oxygen partial pressure due to poisoning phenomenon and the high reactive gases. In addition, it was found that all TiO2 thin films were deposited by different oxygen partial pressure exhibit a good transparentness. Moreover, it was found that the TiO2 thin films deposited by used low oxygen partial pressure and single-anatase phase exhibited the best photocatalytic activity.

Si-N nanowire formation from Silicon nano and microparticles.

2003 ◽  
Vol 789 ◽  
Author(s):  
Chandana Rath ◽  
A. Pinyol ◽  
J. Farjas ◽  
P. Roura ◽  
E. Bertran
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Crystalline Silicon ◽  
Silica Layer ◽  
Whisker Formation ◽  
Low Oxygen ◽  
Partial Pressures ◽  
Precursor Material ◽  
Different Temperatures ◽  
First Time

ABSTRACTWe report silicon nitride whisker formation from hydrogenated amorphous silicon (a-Si:H) nanoparticles grown by PECVD for the first time. We compared the results with the kinetics of whisker formation from ball milled crystalline silicon (c-Si) microparticles. Whisker formation is analyzed at different temperatures (900–1440 °C) and oxygen partial pressures. At temperatures equal or above 1350 C and at low oxygen partial pressure we observe monocrystalline α-Si3N4 whiskers having 30–100 nm diameter and several microns length. By increasing the oxygen partial pressure, the structure of whiskers is completely changed, as shown by electron microscopy. In this case we observe α-Si3N4 whiskers covered by an amorphous silica layer at 1350 C. Finally, when the precursor material is silicon microparticles, thicker (170–330 nm) and longer whiskers are formed.

Ovine ill-thrift in Nova Scotia. 4. The survival at low oxygen partial pressure of fungi isolated from the contents of the ovine rumen

1972 ◽  
Vol 18 (7) ◽  
pp. 1119-1128 ◽  
Author(s):  
D. Brewer ◽  
J. M. Duncan ◽  
S. Safe ◽  
A. Taylor
Keyword(s):  
Carbon Dioxide ◽  
Nova Scotia ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Low Oxygen ◽  
Mucor Rouxii ◽  
Permanent Pasture ◽  
Method Of Determination ◽  
Partial Pressures

Aspergillus fumigatus, Mucor rouxii, and Sporormia minima have been isolated from the rumen contents of sheep grazing permanent pasture at Nappan, Nova Scotia. To determine the ability of these fungi to survive and grow at the low oxygen partial pressure present in the rumen, a method of determination of oxygen, nitrogen, and carbon dioxide has been developed. The lowest partial pressures of oxygen [Formula: see text] and nitrogen that could be detected were 0.0005 cm Hg and the precision of the determination was ±0.001 cm Hg. Carbon dioxide was determined with slightly less precision than achieved for oxygen and nitrogen. Using this method, respiration was detected in cultures of all the fungi named at [Formula: see text] Hg and growth was observed at [Formula: see text] Hg in the case of M. rouxii. It is concluded that all these fungi are capable of survival in the ovine rumen.

Growth and Characterization of ZnO Thin Films Grown by Pulsed Laser Deposition

2011 ◽  
Vol 383-390 ◽  
pp. 6289-6292
Author(s):  
Jian Ting He ◽  
Bo Xue Tan ◽  
Qin Qin Wei ◽  
Yuan Bin Su ◽  
Shu Lian Yang
Keyword(s):  
Thin Films ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Pulsed Laser Deposition ◽  
Photoelectron Spectroscopy ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Zno Thin Films ◽  
X Ray ◽  
Partial Pressures

ZnO thin films were deposited on n-Si (111) substrates at various oxygen partial pressures by pulsed laser deposition (PLD). X-ray diffraction (XRD), scanning electron microscopy (SEM) were used to analyze the influence of the oxygen partial pressure on the crystallization and morphology of the ZnO thin films. An optimal crystallized ZnO thin film was observed at the oxygen partial pressure of 6.5Pa. X-ray photoelectron spectroscopy (XPS) was used to analyze the surface components and distribution status of various elments in ZnO thin films. It was found that ZnO thin films were grown in Zn-rich state.

Sign in / Sign up

Export Citation Format

Share Document