Observations on the growth of barium bismuth oxide thin films

Author(s):  
M G. Norton ◽  
E.S. Hellman ◽  
E.H. Hartford ◽  
C.B. Carter

The bismuthates (for example, Ba1-xKxBiO3) represent a class of high transition temperature superconductors. The lack of anisotropy and the long coherence length of the bismuthates makes them technologically interesting for superconductor device applications. To obtain (100) oriented Ba1-xKxBiO3 films on (100) oriented MgO, a two-stage deposition process is utilized. In the first stage the films are nucleated at higher substrate temperatures, without the potassium. This process appears to facilitate the formation of the perovskite (100) orientation on (100) MgO. This nucleation layer is typically between 10 and 50 nm thick. In the second stage, the substrate temperature is reduced and the Ba1-xKxBiO3 is grown. Continued growth of (100) oriented material is possible at the lower substrate temperature.

2009 ◽  
Vol 67 ◽  
pp. 121-125
Author(s):  
Chattopadhyay Sourav ◽  
Kumar Nath Tapan

Epitaxial Single-crystal ZnO thin films have been grown on c-plane (0001) sapphire by Pulsed Laser Deposition process at different substrate temperatures (300 – 800 °C) with 10-1 mbar oxygen pressure. The thicknesses of the films have been varied by varying number of pulses with a repetition rate of 10 pulse/sec. It is found that the sheet resistivity of ZnO thin films grown on c-plane sapphires are in the order of 10-2 Ω-cm and it increases with increasing substrate temperatures and film thickness. The carrier concentrations and Hall mobility are found to be in the order of 1017 cm-3 and ~195 cm2/V-s, respectively. The Hall mobility slightly decreases with increase of substrate temperature and thickness of the films. It is also found that the ZnO films are structurally uniform and well oriented with perfect wurtzite structure with c/a ratio 5.1. We have also deposited non-epitaxial ZnO films on (100) p-Silicon substrates at the same conditions. From HR FE-SEM micrographs, surface morphology of ZnO films grown at lower substrate temperature are found to be uniform compared to the films grown at higher temperatures showing non-uniformity and misoriented wurtzite structures. However, the surface morphology of ZnO flims grown epitaxially on (0001) sapphire are found to be more uniform and it does not change much with growth temperature. The resistivity of the films grown on p-Silicon at higher temperatures is in the order of 103 Ω-cm whereas films grown at lower substrate temperatures show comparatively lower resistivities (~ 102 Ω-cm). From the recorded UV-Visible absorption spectrum the band gap of the film has been estimated to be 3.38 eV.


2012 ◽  
Vol 706-709 ◽  
pp. 1903-1908 ◽  
Author(s):  
Shozo Inoue ◽  
K. Morino ◽  
Keisuke Yoshiki ◽  
Takahiro Namazu

The purpose of this work is to establish a deposition process of Ti-Ni-Cu films showing shape memory effect in the as-deposited state. 5-µm-thick Ti50Ni35Cu15 films have been deposited onto thermally oxidized (001) Si wafer by triple-source dc magnetron sputtering at various substrate temperatures. Their shape memory behavior were characterized by XRD, DSC measurements and thermal cycling tests under various constant tensile stresses. We have confirmed that crystalline films can be grown directly when the substrate temperature exceeds 400°C. The films deposited at higher than 450°C showed thermoelastic martensitic transformation and their Ms temperature slightly increased with increasing substrate temperature. Since their Ms temperature were found to be higher than 30°C, they can be used as an actuator at RT. These films were also found to have higher critical stress against plastic deformation than the post-deposition crystallized films. We have also tried to fabricate a prototype of micro-actuator and to characterize their actuation behavior and have confirmed that TiNiCu/SiO2 double layered diaphragm showed an actuation response to a pulsed current of more than 100Hz.


1989 ◽  
Vol 4 (5) ◽  
pp. 1238-1242 ◽  
Author(s):  
A. P. Malshe ◽  
S. M. Chaudhari ◽  
S. M. Kanetkar ◽  
S. B. Ogale ◽  
S. V. Rajarshi ◽  
...  

Amorphous carbon films have been deposited on silicon 〈111〉 and quartz substrates by pulsed ruby laser vaporization from pyrolytic graphite. Depositions have been carried out at different substrate temperatures, and the properties of the deposited carbon films have been studied using IR and UV–VIS transmission, ellipsometry, and laser-Raman spectroscopies. Chemical and electrical resistivity measurements have also been performed. It is shown that the film properties depend critically on the substrate temperature and that at the substrate temperature of 50 °C films with substantial proportion of sp3 hybridized orbitals are obtained.


1996 ◽  
Vol 436 ◽  
Author(s):  
J. N. Glosli ◽  
M. R. Philpott ◽  
J. Belak

AbstractMolecular dynamics computer simulations are used to study the effect of substrate temperature on the microstructure of deposited amorphous hydrogenated carbon (a:CH) films. A transition from dense diamond-like films to porous graphite-like films is observed between substrate temperatures of 400K and 600K for a deposition energy of 20 eV. The dense a:CH film grown at 300K and 20 eV has a hardness (˜50 GPa) about half that of a pure carbon (a:C) film grown under the same conditions.


2013 ◽  
Vol 662 ◽  
pp. 413-416
Author(s):  
Yi Shen ◽  
Ruo He Yao

Al films were prepared by DC magnetron sputter deposition at different substrate temperatures. The sheet resistance of the films was measured by four point probe sheet resistance meter, and the film thickness, which was obtained by surface profiling system. The surface and cross-section morphology of the films was observed by AFM and FESEM. As a result, the resistivity of the films decreases obviously as the substrate temperature increases gradually. The higher substrate temperature is, the rougher the films surface is and the larger the grain size is.


2011 ◽  
Vol 1328 ◽  
Author(s):  
KyoungMoo Lee ◽  
Yoshio Abe ◽  
Midori Kawamura ◽  
Hidenobu Itoh

ABSTRACTCobalt hydroxide thin films with a thickness of 100 nm were deposited onto glass, Si and indium tin oxide (ITO)-coated glass substrates by reactively sputtering a Co target in H2O gas. The substrate temperature was varied from -20 to +200°C. The EC performance of the films was investigated in 0.1 M KOH aqueous solution. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy of the samples indicated that Co3O4 films were formed at substrate temperatures above 100°C, and amorphous CoOOH films were deposited in the range from 10 to -20°C. A large change in transmittance of approximately 26% and high EC coloration efficiency of 47 cm2/C were obtained at a wavelength of 600 nm for the CoOOH thin film deposited at -20°C. The good EC performance of the CoOOH films is attributed to the low film density and amorphous structure.


Author(s):  
А.Я. Виноградов ◽  
С.А. Грудинкин ◽  
Н.А. Беседина ◽  
С.В. Коняхин ◽  
М.К. Рабчинский ◽  
...  

AbstractThe structural, electrical, and optical properties of thin graphite-like films produced by magnetron- assisted sputtering onto crystalline silicon and quartz at substrate temperatures in the range from 320 to 620°C are studied. From analysis of the Raman spectra, it is established that, as the substrate temperature is elevated, the crystallite size increases and the concentration of structural defects and the content of amorphous carbon in the phase composition of the films decrease. It is found that, as the substrate temperature is elevated, the maximum of the absorption intensity in the ultraviolet spectral region of the optical absorption spectra shifts to longer wavelengths and the absorption intensity in the visible and near-infrared spectral regions increases. As the deposition temperature is elevated, the conductivity of the films increases from 0.2 Ω^–1 cm^–1 at 320°C to 30 Ω^–1 cm^–1 at 620°C.


2019 ◽  
Author(s):  
Sasan V. Grayli ◽  
Xin Zhang ◽  
Dmitry Star ◽  
Gary Leach

Size, shape and crystallinity play a critical role in the wavelength-dependent optical responses and plasmonic local near-field distributions of metallic nanostructures. While their enhanced local fields can drive new and useful chemical and physical processes, the ability to fabricate shape-controlled single-crystal metal nanostructures and position them precisely on substrates for device applications represents a significant barrier to harnessing their greater potential. Here, we describe a novel electroless deposition process in the presence of anionic additives that yields additive-specific, shape-controlled, single-crystal plasmonic Au nanostructures on Ag(100) and Au(100) substrates. Deposition of Au in the presence of SO<sub>4</sub><sup>2-</sup> ions results in the formation of smooth Au(111)-faceted square pyramids that show large surface enhanced Raman responses. The use of halide additives such as Cl<sup>-</sup> and Br<sup>- </sup>that interact strongly with (100) facets produces highly textured hillock-type structures characterized by edge and screw-type dislocations (Cl<sup>-</sup>), or flat platelet-like features characterized by large area Au(100) terraces with (110) step edges (Br<sup>-</sup>). Use of additive combinations provides structures that comprise characteristics derived from each additive including new square pyramidal structures with dominant Au(110) facets (SO<sub>4</sub><sup>2-</sup>and Br<sup>-</sup>). Finally we demonstrate that this bottom-up electroless deposition process, when combined with top-down lithographic patterning methods, can be used to position shape-controlled, single-crystal Au nanostructures with precise location and orientation on surfaces. We anticipate that this approach will be employed as a powerful new tool to tune the plasmonic characteristics of nanostructures and facilitate their broader integration into device applications.


Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 840
Author(s):  
Da Huang ◽  
Weifeng He ◽  
Xin Cao ◽  
Yang Jiao

In this study, the anti-impact performance of the TiN coatings prepared under various substrate temperatures (35, 200, 400, and 600 °C) were evaluated using a cyclic impact tester under 104 cycles. Moreover, the microstructure and anti-impact performance-related mechanical properties (adhesion strength and nano-hardness) were investigated to reveal the underlying mechanism of how the substrate temperature affects the anti-impact performance of the coatings. The results showed that the substrate temperature has a great influence on the internal stress, nano-hardness, and adhesion strength as well as the anti-impact performance of TiN coatings, and the coatings prepared under 400 °C exhibit the best impact resistance. The small internal stress, strong adhesion strength as well as high hardness and H3/E2 value for the 400 °C prepared coatings are the main contributes.


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