scholarly journals In Situ Initial Growth Studies of (Sr, Ca)CuO2 ON SrTiO3 by High Pressure Rheed

1997 ◽  
Vol 502 ◽  
Author(s):  
Gertjan Koster ◽  
Guus J. H. M. Runders ◽  
Dave H. A. Blank ◽  
Horst Rogalla
Keyword(s):  
High Pressure ◽  
Pulsed Laser ◽  
High Energy ◽  
Initial Growth ◽  
Force Microscopy ◽  
Atomic Force ◽  
Growth Studies ◽  
Layer Structures ◽  
First Results

ABSTRACTThe initial growth of pulsed laser deposited SrCuO2 (SCO) and CaCuO2 (CCO) on SrTiO3 has been studied using high pressure Reflection High Energy Electron Diffraction (RHEED) and Atomic Force Microscopy (AFM). For this, we developed a Pulsed Laser Deposition (PLD)- RHEED system, with the possibility to study the growth and to monitor the growth rates, in situ, at typical PLD pressures (10–50 Pa). In case of depositing oxide materials, high oxygen pressures are desired. Moreover, crystallinity can be improved using higher oxygen pressures and therefore higher temperatures. With this technique we are able to obtain atomically flat films, a first step towards multi-layer structures.In this paper we present the initial growth studies of SCO and first results incorporating CCO layers in a SCO matrix.

scholarly journals In Situ Initial Growth Studies of SrTiO3 on SrTiO3 by Time Resolved High Pressure RHEED

1998 ◽  
Vol 526 ◽  
Author(s):  
Gertjan Koster ◽  
Guus J.H.M. Rijnders ◽  
Dave H.A. Blank ◽  
Horst Rogalla
Keyword(s):  
High Pressure ◽  
Pulsed Laser ◽  
High Energy ◽  
Initial Growth ◽  
Time Resolved ◽  
Force Microscopy ◽  
Atomic Force ◽  
Different Temperatures ◽  
Substrate Surfaces

AbstractThe initial growth of pulsed laser deposited SrTiO3 on SrTiO3 has been studied using high pressure Reflection High Energy Electron Diffraction (RHEED) and Atomic Force Microscopy (AFM). For this, we developed a Pulsed Laser Deposition (PLD)-RHEED system, with the possibility to study the growth and to monitor the growth rates, in situ, at typical PLD pressures (10-50 Pa). Using perfect single crystal SrTiO3 substrate surfaces, we observe true 2D intensity oscillations at different temperatures. Simultaneously, information on the diffusion of the deposited material on the surface could be extracted from the relaxation of the intensity after each laser pulse. The characteristic times depend on pressure and temperature as well as the 2D coverage during growth.

Interface and Luminescence Properties of Pulsed Laser Deposited MgxZn1-xO/ZnO Quantum Wells with Strong Confinement

2006 ◽  
Vol 957 ◽  
Author(s):  
Susanne Heitsch ◽  
Gregor Zimmermann ◽  
Alexander Müller ◽  
Jörg Lenzner ◽  
Holger Hochmuth ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Stark Effect ◽  
Pulsed Laser ◽  
Energy Shift ◽  
High Energy ◽  
Interface Roughness ◽  
Force Microscopy ◽  
Quantum Confined Stark Effect ◽  
Barrier Layers ◽  
Atomic Force

ABSTRACTMgxZn1-xO/ZnO/MgxZn1-xO quantum wells (QWs) (0.12 ≤ x ≤ 0.15) have been grown on a-plane sapphire substrates by pulsed laser deposition. The nominal ZnO well layer thickness lies between 1.2 nm and 6 nm. Atomic force microscopy (AFM) investigations at ZnO/MgxZn1−xO heterostructures show the film-like structure of the ZnO layers. Their root mean square surface roughness of ∼ 0.5 nm gives information about the interface roughness in the QWs. AFM results from the MgxZn1−xO barrier layers show the same surface structure and roughness. We confirmed the lateral homogeneity of the Mg distribution in the MgxZn1−xO barrier layers by scanning cathodoluminescence measurements. The QWs show a bright and laterally homogeneous luminescence, suggesting good crystalline quality of the ZnO wells. The measured QW photoluminescence energies agree well with calculated values and display the presence of the quantum-confined Stark effect. As a result of quantum confinement a high-energy shift of the ZnO excitonic photoluminescence of 222 meV is observed in the thinnest QW.

Micro Raman Spectroscopy of Silicon Nanocrystals Produced by Picosecond Pulsed Laser Ablation

2002 ◽  
Vol 738 ◽  
Author(s):  
M. H. Wu ◽  
R. Mu ◽  
A. Ueda ◽  
D. O. Henderson ◽  
B. Vlahovic
Keyword(s):  
Laser Ablation ◽  
Raman Spectra ◽  
Silicon Nanocrystals ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Size Distributions ◽  
Laser Plume ◽  
Force Microscopy ◽  
Atomic Force

ABSTRACTPulsed laser ablation has been used to produce silicon nanocrystals. Variation of the laser fluence, backing gas type and pressure result in nanocrystals with controllable size distributions. Properties of nanocrystals produced with this method also depend on the distance of the nanocrystal from the center of the laser plume. Correlated atomic force microscopy and in-situ micro-Raman measurements confirm that particle size decreases as distance from the plume center increases. Silicon peaks in the micro raman spectra taken at increasing distance from plume center show considerable differences in both center energy and width. Confocal micro raman spectra from thicker (> 10 micron) samples show little variation with depth, in contrast with porous silicon samples.

Drastic Change in the Gan Film Quality by In-Situ Controlling Surface Reconstructions In Gsmbe

1997 ◽  
Vol 482 ◽  
Author(s):  
X. Q. Shen ◽  
S. Tanaka ◽  
S. Iwai ◽  
Y. Aoyagi
Keyword(s):  
Growth Conditions ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Gas Source ◽  
Atomic Force ◽  
Surface Reconstructions ◽  
Gan Film

AbstractGaN growth was performed on 6H-SiC (0001) substrates by gas-source molecular beam epitaxy (GSMBE), using ammonia (NH3) as a nitrogen source. Two kinds of reflection high-energy electron diffraction (RHEED) patterns, named (1×1) and (2×2), were observed during the GaN growth depending on the growth conditions. By careful RHEED study, it was verified that the (1×1) pattern was corresponded to a H2-related nitrogen-rich surface, while (2×2) pattern was resulted from a Ga-rich surface. By x-ray diffraction (XRD), photoluminescence (PL) and atomic force microscopy (AFM) characterizations, it was found that the GaN quality changed drastically grown under different RHEED patterns. GaN film grown under the (1×1) RHEED pattern showed much better qualities than that grown under the (2×2) one.

Preparation of (111)-Oriented Pt Electrode Films with Quasi-Monocrystal Properties on MgO/TiN Buffered Si(100) by PLD

2007 ◽  
Vol 280-283 ◽  
pp. 823-826 ◽  
Author(s):  
Tong Lai Chen ◽  
Xiao Min Li
Keyword(s):  
High Energy ◽  
Layer Growth ◽  
Atomic Scale ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
Pt Electrode ◽  
Force Microscopy ◽  
Atomic Force

Atomic-scale smooth Pt electrode films have been deposited on MgO/TiN buffered Si (100) by the pulsed laser deposition (PLD) technique. The whole growth process of the multilayer films was monitored by using in-situ reflection high energy electron diffraction (RHEED) apparatus. The Pt/MgO/TiN/Si(100) stacked structure was also characterized by X-ray diffraction (XRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM). The HREED observations show that the growth mode of the Pt electrode film is 2D layer-by-layer growth. It is found that the (111)-oriented Pt electrode film has a crystallinity comparable to that of monocrystals. The achievement of the quasi-single-crystal Pt electrode film with an atomic-scale smooth surface is ascribed to the improved crystalline quality of the MgO film.

Compliance at the GaSb/GaP Interface by Misfit Dislocations Array

2011 ◽  
Vol 324 ◽  
pp. 85-88
Author(s):  
Salim El Kazzi ◽  
Ludovic Desplanque ◽  
Christophe Coinon ◽  
Yi Wang ◽  
Pierrre Ruterana ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Energy ◽  
Misfit Dislocations ◽  
Initial Growth ◽  
Electron Diffraction Analysis ◽  
High Energy Electron ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

We study the initial growth of 10 monolayers (MLs) of GaSb on a (001) GaP substrate. Transmission electron microscopy and reflection high energy electron diffraction analysis show that an Sb-rich GaP surface promotes the formation of a 90° misfit dislocation array at the epi-substrate interface. Using atomic force microscopy, we investigate the influence of the growth temperature and the growth rate on the formation and the shape of GaSb islands.

MBE Growth of IV-VI Nanowires on a Self-organized Template

2010 ◽  
Vol 1258 ◽  
Author(s):  
Lee Andrew Elizondo ◽  
Patrick McCann ◽  
Joel Keay ◽  
Matthew Johnson
Keyword(s):  
Quantum Wires ◽  
High Energy ◽  
Ex Situ ◽  
Mbe Growth ◽  
One Dimensional ◽  
Force Microscopy ◽  
Self Organized ◽  
Atomic Force ◽  
Low Dimensional

AbstractWe present the experimental results for the first known molecular beam epitaxy (MBE) growth of quasi-one-dimensional PbSe wires on technologically relevant silicon.In this work, we describe the growth and characterization of low-dimensional IV-VI semiconductors as they evolve from one-dimensional dot/dot-chains to one-dimensional structures on a self-organized template epitaxially grown on Si(110). In situ and ex situ characterization were performed at various stages throughout growth by reflection high energy electron diffraction, scanning electron microscopy, and non-contact atomic force microscopy. Initial growths resulted in some preferential alignment of the PbSe dot-chains parallel to the self-organized template in the [-110] direction. By reducing the substrate temperature and increasing the supplemental Se flux, the morphology of dot-chains extend into lengthened one-dimensional structures. This is an important milestone in the fabrication of PbSe quantum wires on technologically relevant silicon.

Direct Growth of AIN Thin Layer on (111)Si Substrate by RF-MBE

1998 ◽  
Vol 512 ◽  
Author(s):  
Naoki Ohshima ◽  
Hiroo Yonezu ◽  
Shinobu Uesugi ◽  
Keisuke Gotoh ◽  
Seiji Yamahira
Keyword(s):  
High Energy ◽  
Rf Plasma ◽  
Si Substrate ◽  
Plasma Gun ◽  
Force Microscopy ◽  
Atomic Force ◽  
Nitridation Process ◽  
Migration Enhanced Epitaxy ◽  
Direct Growth

ABSTRACTThe nitridation process of (111)Si surface has been studied by in-situ reflection high-energy electron diffraction (RHEED) and Auger electron spectroscopy (AES) measurements. It has been clarified that the nitridation of the Si surface is occurred even if the shutter of the discharged rf-plasma gun is closed. The growth process of AIN epilayer on the Si substrate by migration enhanced epitaxy (MEE) has been investigated by in-situ RHEED and atomic force microscopy (AFM) observations. It has been found that the AIN epilayer is directly grown on (111)Si by MEE growth.

PREPARATION AND CHARACTERIZATION OF LaFeO3 THIN FILMS ON (100) SrTiO3 SUBSTRATES BY PULSED LASER DEPOSITION

2011 ◽  
Vol 01 (03) ◽  
pp. 363-367 ◽  
Author(s):  
HONG LIU ◽  
JIANGUO ZHU ◽  
DINGQUAN XIAO
Keyword(s):  
Pulsed Laser Deposition ◽  
Quantum Interference ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

A single-crystalline, crack-free, epitaxial (100)c LaFeO3 films were in situ grown by pulsed laser deposition on (100) SrTiO3 substrates. X-ray diffraction, atomic force microscopy and transmission electron microscopy reveal that the LaFeO3 films have high crystalline quality, a very smooth surface, and an atomically sharp LaFeO3/SrTiO3 interface. The magnetic properties of the LaFeO3 films were obtained by a superconducting quantum interference device magnetometry. The saturated magnetization and coercive field of LaFeO3 films are 14 emu/cm3 and 600 Oe, respectively.

Sequential Phase Formation during Reactive Diffusion of a Nanometric-Thick Mn Film on Ge(111)

2011 ◽  
Vol 172-174 ◽  
pp. 579-584 ◽  
Author(s):  
Omar Abbes ◽  
Feng Xu ◽  
Alain Portavoce ◽  
Khalid Hoummada ◽  
Vinh Le Thanh ◽  
...  
Keyword(s):  
Magnetic Layer ◽  
High Energy ◽  
Reactive Diffusion ◽  
Ferromagnetic Phase ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Spin Polarized ◽  
First Results ◽  
Sequential Phase

In recent years, spintronics whose principle is based on controlling the spin of electrons in semiconductor layers is presented as a complementary or even an alternative solution for production of logic devices in microelectronics. It relies on the fact that electric current in a magnetic layer can be spin polarized. Manufacture of such components is based on the use of materials or heterostructures whose electronic properties depend on their magnetic state. The magnetic Mn-Ge system is interesting because of its possible development at high Curie temperature and its integration on Si substrate. Among all of the Mn-Ge phase compounds of the diagram, Mn5Ge3 seems the most interesting one for spintronics applications: it is a stable and ferromagnetic phase at room temperature. In this paper, we present first results of the study, by Reflection High Energy Electron Diffraction (RHEED), X-ray diffraction (XRD) and Atomic Force Microscopy (AFM), of the sequence of formation of the MnxGey phases in the case of reaction of a nanometric-thick Mn film (200nm) deposited by MBE on Ge (111).

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