scholarly journals Scanning X-ray nanodiffraction from ferroelectric domains in strained K0.75Na0.25NbO3 epitaxial films grown on (110) TbScO3

2017 ◽  
Vol 50 (2) ◽  
pp. 519-524 ◽  
Author(s):  
Martin Schmidbauer ◽  
Michael Hanke ◽  
Albert Kwasniewski ◽  
Dorothee Braun ◽  
Leonard von Helden ◽  
...  
Keyword(s):  
Epitaxial Layer ◽  
Elastic Anisotropy ◽  
Elastic Strain Energy ◽  
Epitaxial Films ◽  
Linear Elasticity Theory ◽  
X Ray ◽  
Probe Size ◽  
Ferroelectric Domains ◽  
Elastic Strain Energy Density ◽  
Domain Variant

Scanning X-ray nanodiffraction on a highly periodic ferroelectric domain pattern of a strained K0.75Na0.25NbO3 epitaxial layer has been performed by using a focused X-ray beam of about 100 nm probe size. A 90°-rotated domain variant which is aligned along [1{\overline 1}2]TSO has been found in addition to the predominant domain variant where the domains are aligned along the [{\overline 1}12]TSO direction of the underlying (110) TbScO3 (TSO) orthorhombic substrate. Owing to the larger elastic strain energy density, the 90°-rotated domains appear with significantly reduced probability. Furthermore, the 90°-rotated variant shows a larger vertical lattice spacing than the 0°-rotated domain variant. Calculations based on linear elasticity theory substantiate that this difference is caused by the elastic anisotropy of the K0.75Na0.25NbO3 epitaxial layer.

scholarly journals Structural Studies of the Epitaxial Layer of a Substitutional Solid Solution (GaAs)1−x(ZnSe)x with Nanocrystals

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
A. S. Saidov ◽  
Sh. N. Usmonov ◽  
D. V. Saparov
Keyword(s):  
Solid Solution ◽  
Epitaxial Layer ◽  
Surface Region ◽  
Substitutional Solid Solution ◽  
Epitaxial Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Ordered Array

In this work, we explored the possibility of growing a substitutional solid solution (GaAs)1−x(ZnSe)x with an ordered array of nanosize crystals on GaAs (100) substrates. Grown epitaxial films were investigated by the X-ray diffraction analysis method. The chemical composition of the grown epitaxial films was determined by a X-ray microanalyzer, along the thickness of the epitaxial layer. The photoluminescence spectrum was studied and a peak is observed at λmax = 465 nm, corresponding to the width of the band gap of zinc selenide EZnSe = 2.67 eV, which is apparently due to the nanocrystals ZnSe, disposed in the surface region of the epitaxial film of a solid solution (GaAs)1−x(ZnSe)x. Size of nanocrystals were evaluated by an atomic force microscopy.

High spatial resolution x-ray microanalysis of interfaces

1995 ◽  
Vol 53 ◽  
pp. 284-285
Author(s):  
J. R. Michael
Keyword(s):  
Spatial Resolution ◽  
Electron Probe ◽  
Solid Angle ◽  
Collection Efficiency ◽  
Spatial Scales ◽  
Energy Dispersive Spectrometer ◽  
X Rays ◽  
X Ray ◽  
Probe Size ◽  
Brightness Field

X-ray microanalysis in the analytical electron microscope (AEM) refers to a technique by which chemical composition can be determined on spatial scales of less than 10 nm. There are many factors that influence the quality of x-ray microanalysis. The minimum probe size with sufficient current for microanalysis that can be generated determines the ultimate spatial resolution of each individual microanalysis. However, it is also necessary to collect efficiently the x-rays generated. Modern high brightness field emission gun equipped AEMs can now generate probes that are less than 1 nm in diameter with high probe currents. Improving the x-ray collection solid angle of the solid state energy dispersive spectrometer (EDS) results in more efficient collection of x-ray generated by the interaction of the electron probe with the specimen, thus reducing the minimum detectability limit. The combination of decreased interaction volume due to smaller electron probe size and the increased collection efficiency due to larger solid angle of x-ray collection should enhance our ability to study interfacial segregation.

Practical Importance of Spatial Resolution and Analytical Sensitivity in AEM X-ray Microanalysis

1990 ◽  
Vol 48 (2) ◽  
pp. 432-433
Author(s):  
J. Zhang ◽  
D.B. Williams ◽  
J.I. Goldstein
Keyword(s):  
Spatial Resolution ◽  
Practical Importance ◽  
Beam Current ◽  
Specimen Thickness ◽  
Analytical Sensitivity ◽  
Related Factors ◽  
X Ray ◽  
Probe Size ◽  
Excitation Volume ◽  
Two Parameters

Analytical sensitivity and spatial resolution are important and closely related factors in x-ray microanalysis using the AEM. Analytical sensitivity is the ability to distinguish, for a given element under given conditions, between two concentrations that are nearly equal. The analytical sensitivity is directly related to the number of x-ray counts collected and, therefore, to the probe current, specimen thickness and counting time. The spatial resolution in AEM analysis is determined by the probe size and beam broadening in the specimen. A finer probe and a thinner specimen give a higher spatial resolution. However, the resulting lower beam current and smaller X-ray excitation volume degrade analytical sensitivity. A compromise must be made between high spatial resolution and an acceptable analytical sensitivity. In this paper, we show the necessity of evaluating these two parameters in order to determine the low temperature Fe-Ni phase diagram.A Phillips EM400T AEM with an EDAX/TN2000 EDS/MCA system and a VG HB501 FEG STEM with a LINK AN10 EDS/MCA system were used.

X-ray diffraction analysis of a selectively grown InGaAsP epitaxial layer

2001 ◽  
Vol 90 (7) ◽  
pp. 3255-3262 ◽  
Author(s):  
Kiichi Nakashima ◽  
Yoshihiro Kawaguchi
Keyword(s):  
Diffraction Analysis ◽  
Epitaxial Layer ◽  
X Ray Diffraction ◽  
X Ray

Characterization of III-nitride Based Schottky UV Detectors with Wide Detectable Wavelength Range (360–10 nm) using Synchrotron Radiation

2003 ◽  
Vol 798 ◽  
Author(s):  
Atsushi Motogaito ◽  
Kazumasa Hiramatsu ◽  
Yasuhiro Shibata ◽  
Hironobu Watanabe ◽  
Hideto Miyake ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Schottky Barrier ◽  
Wavelength Range ◽  
Epitaxial Layer ◽  
Device Performance ◽  
Uv Detectors ◽  
X Ray ◽  
High Responsivity ◽  
Vacuum Uv

ABSTRACTCharacterizations of transparent Schottky barrier GaN and AlGaN UV detectors in the vacuum UV (VUV) and soft X-ray (SX) region using synchrotron radiation are described. In the GaN UV detectors, the responsivity achieved about 0.05 A/W at 95 eV (13 nm). Thus, their device performance is shown between 3.4 and 100 eV (10 and 360 nm). Furthermore, the high responsivity spectra were realized by using AlGaN Schottky UV detectors consisting of Al0.5Ga0.5N on AlN epitaxial layer.

Influence of LaNiO3 as an Electrode on the Properties of Ferroelectric Oxides

2000 ◽  
Vol 623 ◽  
Author(s):  
R. Kalare ◽  
M. Vedawyas ◽  
A. Kumar
Keyword(s):  
Ferroelectric Properties ◽  
Ferroelectric Thin Film ◽  
Memory Device ◽  
Epitaxial Films ◽  
Laser Deposition ◽  
Oxide Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Potential Electrode ◽  
Ferroelectric Oxides

AbstractAn electrode plays an important role in realising a ferroelectric thin film as a potential memory device. We have investigated LaNiO3 (LNO) as a potential electrode material and evaluated the ferroelectric properties of oxide materials like strontium bismuth tantalate (SBT) and barium titanate(BT). We have successfully deposited epitaxial films of LNO on Pt coated Si(100) and LaAlO3 (LAO) substrates using the pulsed excimer laser deposition technique. We are able to grow high quality SBT and BT films on top of this LNO layer. The X-ray diffraction revealed the epitaxy of the LNO, SBT and BT films. The ferroelectric properties of SBTand BT were investigated using the RT66A ferroelectric tester.

Thermal Strain Study of Almost Lattice-Matched Epitaxial InuGa1-uAs1-vP1-v Films on InP(100) Substrates

1989 ◽  
Vol 160 ◽  
Author(s):  
G. Bai ◽  
M-A. Nicolet ◽  
S.-J. Kim ◽  
R.G. Sobers ◽  
J.W. Lee ◽  
...  
Keyword(s):  
Room Temperature ◽  
Epitaxial Film ◽  
Lattice Mismatch ◽  
Thermal Strain ◽  
Growth Direction ◽  
Epitaxial Films ◽  
Double Crystal ◽  
X Ray ◽  
Lattice Matched ◽  
Coherent Interfaces

AbstractSingle layers of ~ 0.5µm thick InuGa1-uAs1-vPv (0.52 < u < 0.63 and 0.03 < v < 0.16) were grown epitaxially on InP(100) substrates by liquid phase epitaxy at ~ 630°C. The compositions of the films were chosen to yield a constant banndgap of ~ 0.8 eV (λ = 1.55 µm) at room temperature. The lattice mismatch at room temperature between the epitaxial film and the substrate varies from - 4 × 10-3 to + 4 × 10-3. The strain in the films was characterized in air by x-ray double crystal diffractometry with a controllable heating stage from 23°C to ~ 700°C. All the samples have an almost coherent interfaces from 23°C to about ~ 330°C with the lattice mismatch accomodated mainly by the tetragonal distortion of the epitaxial films. In this temperature range, the x-ray strain in the growth direction increases linearly with temperature at a rate of (2.0 ± 0.4) × 10-6/°C and the strain state of the films is reversible. Once the samples are heated above ~ 300°C, a significant irreversible deterioration of the epitaxial films sets in.

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