Effects of Sn substitution in SrRuO3 epitaxial films

Single crystal films in (001) orientation, about 1500 Å thick, were produced by R-F sputtering of Al + 4 wt % Cu onto cleaved KCl at 150°C substrate temperature. The as-deposited films contained numerous θ-CuAl2 particles (C16 structure) about 0.1μ in size. They were transferred onto Mo screens, solution treated and rapidly cooled (within about ½ min) so as to retain a homogeneous solid solution. Subsequently, the films were aged in vacuum at various temperatures in order to induce precipitation and to compare structures and morphologies of precipitate particles in Al-Cu films with those found in age hardened bulk material.Aging for 3 weeks at 60°C or 48 hrs at 100°C did not produce any detectable change in high resolution micrographs or diffraction patterns. In this range Guinier-Preston zones (GP) form in quenched bulk material. The absence of GP in the present experiments in this aging range is perhaps due to the cooling rate employed, which might be more equivalent to an aged and reverted bulk material than to a quenched one.

Download Full-text

Epitaxial growth manner and structure of superconducting oxide films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100173145 ◽

1990 ◽

Vol 48 (4) ◽

pp. 2-3

Author(s):

Yoshichika Bando ◽

Takahito Terashima ◽

Kenji Iijima ◽

Kazunuki Yamamoto ◽

Kazuto Hirata ◽

...

Keyword(s):

Ultrathin Films ◽

Film Surface ◽

High Energy ◽

Epitaxial Films ◽

Layer By Layer ◽

Initial Growth ◽

In Situ Growth ◽

High Quality ◽

Activated Reactive Evaporation

The high quality thin films of high-Tc superconducting oxide are necessary for elucidating the superconducting mechanism and for device application. The recent trend in the preparation of high-Tc films has been toward “in-situ” growth of the superconducting phase at relatively low temperatures. The purpose of “in-situ” growth is to attain surface smoothness suitable for fabricating film devices but also to obtain high quality film. We present the investigation on the initial growth manner of YBCO by in-situ reflective high energy electron diffraction (RHEED) technique and on the structural and superconducting properties of the resulting ultrathin films below 100Å. The epitaxial films have been grown on (100) plane of MgO and SrTiO, heated below 650°C by activated reactive evaporation. The in-situ RHEED observation and the intensity measurement was carried out during deposition of YBCO on the substrate at 650°C. The deposition rate was 0.8Å/s. Fig. 1 shows the RHEED patterns at every stage of deposition of YBCO on MgO(100). All the patterns exhibit the sharp streaks, indicating that the film surface is atomically smooth and the growth manner is layer-by-layer.

Download Full-text

In-depth Analysis of the Impurities in GaN

MRS Internet Journal of Nitride Semiconductor Research ◽

10.1557/s1092578300002064 ◽

1996 ◽

Vol 1 ◽

Cited By ~ 3

Author(s):

A. P. Kovarsky ◽

V. S. Strykanov

Keyword(s):

Secondary Ion Mass Spectrometry ◽

Dynamic Range ◽

Detection Limits ◽

Background Level ◽

Epitaxial Films ◽

Depth Analysis ◽

Lower Detection ◽

Minimum Detection Level ◽

Ion Yields ◽

Secondary Ion

GaN epitaxial films were analyzed by Secondary Ion Mass Spectrometry (SIMS). Standard implanted samples were used to determine the appropriate analytical conditions for analysis of impurities. The dose and energy of implantation for selected elements (Mg, Al, Si, Zn, Cd, H, C and O) were chosen so the maximum impurity concentration was not more than 1020 atoms/cm3. The optimum analysis conditions were ascertained from the standards for each element, and the detection limits were deduced from the background levels of the implantation profiles. We demonstate that lower detection limits of 1015 atoms/cm3 with a dynamic range 103 − 105 are possible. Zn and Cd have low ion yields, so the minimum detection level for these elements is the background level of the detector. The detection limits of the other elements are determined by the contamination of an initial GaN matrix.

Download Full-text

Study of Grown-In Defects Verses Growth Parameters in GaAs and Al(x)Ga(1-x)AS Epitaxial Films Grown by LPE and MOCVD Techniques.

10.21236/ada173736 ◽

1985 ◽

Author(s):

Sheng S. Li

Keyword(s):

Growth Parameters ◽

Epitaxial Films

Download Full-text

Optical absorption by Nd3+ and Gd3+ ions in epitaxial films grown on Gd3Ga5O12 substrates from a lead-containing solution melt

Physics of the Solid State ◽

10.1134/1.1767239 ◽

2004 ◽

Vol 46 (6) ◽

pp. 1030-1036 ◽

Cited By ~ 4

Author(s):

V. V. Randoshkin ◽

N. V. Vasil’eva ◽

V. G. Plotnichenko ◽

Yu. N. Pyrkov ◽

S. V. Lavrishchev ◽

...

Keyword(s):

Optical Absorption ◽

Epitaxial Films

Download Full-text

Rapid Epitaxial Growth of Si and SiGe Mono-Crystalline Films on Silicon-on-Glass Substrates by Reactive CVD Using SiH4, GeH4, and F2

MRS Proceedings ◽

10.1557/opl.2012.867 ◽

2012 ◽

Vol 1426 ◽

pp. 331-337

Author(s):

Hiroshi Noge ◽

Akira Okada ◽

Ta-Ko Chuang ◽

J. Greg Couillard ◽

Michio Kondo

Keyword(s):

Epitaxial Growth ◽

Heating Temperature ◽

Exothermic Reaction ◽

Epitaxial Films ◽

Si Substrates ◽

Glass Substrates ◽

Good Crystallinity ◽

Crystalline Films ◽

Si Films ◽

First Time

ABSTRACTWe have succeeded in the rapid epitaxial growth of Si, Ge, and SiGe films on Si substrates below 670 ºC by reactive CVD utilizing the spontaneous exothermic reaction between SiH4, GeH4, and F2. Mono-crystalline SiGe epitaxial films with Ge composition ranging from 0.1 to 1.0 have been successfully grown by reactive CVD for the first time.This technique has also been successfully applied to the growth of these films on silicon-on-glass substrates by a 20 - 50 ºC increase of the heating temperature. Over 10 μm thick epitaxial films at 3 nm/s growth rate are obtained. The etch pit density of the 5.2 μm-thick Si0.5Ge0.5 film is as low as 5 x 106 cm-2 on top. Mobilities of the undoped SiGe and Si films are 180 to 550 cm2/Vs, confirming the good crystallinity of the epitaxial films.

Download Full-text

The effects of Sn substitution on the phase, microstructure, and dielectric properties of 0.94(Bi0.5Na0.5)TiO3–0.06Ba(Zr0.1Ti0.9)O3 ceramic system

Chemical Physics Impact ◽

10.1016/j.chphi.2021.100015 ◽

2021 ◽

Vol 2 ◽

pp. 100015

Author(s):

Abdul Manan ◽

Murad Ali Khan ◽

Arbab Safeer Ahmad ◽

Atta Ullah ◽

Arshad Hussain wazir ◽

...

Keyword(s):

Dielectric Properties ◽

Ceramic System ◽

Sn Substitution

Download Full-text

Alkali-deficiency driven charged out-of-phase boundaries for giant electromechanical response

Nature Communications ◽

10.1038/s41467-021-23107-x ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Haijun Wu ◽

Shoucong Ning ◽

Moaz Waqar ◽

Huajun Liu ◽

Yang Zhang ◽

...

Keyword(s):

Thin Films ◽

Temperature Stability ◽

Epitaxial Films ◽

Polarization Rotation ◽

Phase Boundaries ◽

Film Properties ◽

New Strategy ◽

The Matrix ◽

Opposing Effects ◽

Severe Deterioration

AbstractTraditional strategies for improving piezoelectric properties have focused on phase boundary engineering through complex chemical alloying and phase control. Although they have been successfully employed in bulk materials, they have not been effective in thin films due to the severe deterioration in epitaxy, which is critical to film properties. Contending with the opposing effects of alloying and epitaxy in thin films has been a long-standing issue. Herein we demonstrate a new strategy in alkali niobate epitaxial films, utilizing alkali vacancies without alloying to form nanopillars enclosed with out-of-phase boundaries that can give rise to a giant electromechanical response. Both atomically resolved polarization mapping and phase field simulations show that the boundaries are strained and charged, manifesting as head-head and tail-tail polarization bound charges. Such charged boundaries produce a giant local depolarization field, which facilitates a steady polarization rotation between the matrix and nanopillars. The local elastic strain and charge manipulation at out-of-phase boundaries, demonstrated here, can be used as an effective pathway to obtain large electromechanical response with good temperature stability in similar perovskite oxides.

Download Full-text