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Effects of Mismatch Strain and Alloy Composition on the Formation of InAs Islands on InAlAs Templates

Y. CORDIER,
1,3 P. MISKA,
1 and D. FERRE2
1.—Institut d’Electronique et de Microélectronique du Nord, U.M.R.-C.N.R.S 8520,
Avenue Poincaré, Université de Lille 1, BP 69, 59652 Villeneuve d’Ascq Cedex, France.
2.—Laboratoire Structure et Propriétés de l’Etat Solide, URA 234, Université de Lille 1,
59650 Villeneuve d’Ascq, France. 3.—e-mail: yvon.cordier@iemn.univ-lille1.fr
InAs islands self-assembled on InAlAs layers lattice mismatched on GaAs
substrates have been grown by molecular beam epitaxy. Both pseudomorphic
and metamorphic InAlAs buffer layers were used as a template to investigate the
effects of strain relaxation on the formation of the islands. The effect of alloy
composition in the metamorphic templates is shown on the density and the shape
of …

Low temperature step-graded InAlAs/GaAs metamorphic buffer layers grown by molecular beam epitaxy

X Z Shang1,3
,SDWu2
, C Liu1
,WXWang2
, LWGuo2
, Q Huang2
and J M Zhou2
1
School of Physics and Technology, Wuhan University, Wuhan 430072, Hubei, People’s
Republic of China
2
State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of
Sciences, Beijing 100080, People’s Republic of China
E-mail: xunzhong@acc-lab.whu.edu.cn
Received 8 December 2005
Published 20 April 2006
Online at stacks.iop.org/JPhysD/39/1800
Abstract
Low-temperature step-graded InAlAs metamorphic buffer layers on GaAs
substrate grown by molecular beam epitaxy were investigated. The strain
relaxation and the composition of the top InAlAs layer were determined by
high-resolution triple-axis x-ray diffraction measurements, which show that
the top InAlAs layer is nearly fully relaxed. Surface morphology was
observed by reflection high-energy electron diffraction pattern and …

Oxide Nanoelectrolics

Cheng Cen,
Stefan Thiel,
Jochen Mannhart,
Jeremy Levy
Electronic confinement at nanoscale dimensions remains a central means of science and
technology. We demonstrate nanoscale lateral confinement of a quasi–two-dimensional electron
gas at a lanthanum aluminate–strontium titanate interface. Control of this confinement using an
atomic force microscope lithography technique enabled us to create tunnel junctions and field-effect
transistors with characteristic dimensions as small as 2 nanometers. These electronic devices can be
modified or erased without the need for complex lithographic procedures. Our on-demand
nanoelectronics fabrication platform has the potential for widespread technological application.

Sedimentation processes and new age constraints on rifting stages in Lake Baikal: results of deep-water drilling

Abstract With this paper we present a first attempt to
combine the direct results on lithology, composition
and age dating in the boreholes BDP-93, BDP-96 and
BDP-97 with geological and seismic data from the areas
where those sections were drilled. The sedimentary
environments represented by the BDP boreholes are
markedly different and possess characteristic litholog-
ical features. The results of the deep drilling provide
the essential means for testing …

Al2O3 Physical properties

W. Y. Ching,
Lizhi Ouyang,
Paul Rulis,
and Hongzhi Yao1
Department of Physics, University of Missouri-Kansas City, Kansas City, Missouri 64110, USA
Department of Physics and Mathematics, Tennessee State University, Nashville, Tennessee 37211, USA
Based on the most recently determined noncubic structure for -Al2O3 by Menendez-Proupin and Gutierrez,
a comprehensive list of physical properties is investigated theoretically. These include lattice dynamics and
phonon spectra, elastic constants and bulk structural parameters, electronic structure and interatomic bonding,
optical properties, and x-ray absorption near-edge structure XANES spectra. Compared to similar calcula-
tions of -Al2O3, we find a smaller lowest zone-center vibrational mode at 97.6 cm−1
, a lower heat capacity,
a smaller bulk modulus, and …

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