Search results for "Annealing"

SAMSLAM: Simulated Annealing Monocular SLAM

2013

This paper proposes a novel monocular SLAM approach. For a triplet of successive keyframes, the approach inteleaves the registration of the three 3D maps associated to each image pair in the triplet and the refinement of the corresponding poses, by progressively limiting the allowable reprojection error according to a simulated annealing scheme. This approach computes only local overlapping maps of almost constant size, thus avoiding problems of 3D map growth. It does not require global optimization, loop closure and back-correction of the poses.

Effect of high temperature annealing (T > 1650 °C) on the morphological and electrical properties of p-type implanted 4H-SiC layers

2019

This work reports on the effect of high temperature annealing on the electrical properties of p-type implanted 4H-SiC. Ion implantations of Aluminum (Al) at different energies (30-200 keV) were carried out to achieve 300 nm thick acceptor box profiles with a concentration of about 10(20) at/cm(3). The implanted samples were annealed at high temperatures (1675-1825 degrees C). Morphological analyses of the annealed samples revealed only a slight increase of the surface roughness RMS up to 1775 degrees C, while this increase becomes more significant at 1825 degrees C (RMS = 1.2 nm). Room temperature Hall measurements resulted in a hole concentration in the range 0.65-1.34 x 10(18)/cm(3) and m…

Quantum well intermixing in GaInNAs/GaAs structures

2003

We report on the characteristics of quantum well intermixing in GaInNAs/GaAs structures of differing N content. Rapid thermal annealing combined with SiO2 caps deposited on the surface of the samples is used to disorder 1.3 mum GaInNAs/GaAs multiquantum wells which have been preannealed in-situ to the stage of blueshift saturation. The different effects of two capping layer deposition techniques on the interdiffusion of In-Ga have been compared, particular regarding the role of sputtering processes. The dependence of quantum well intermixing-induced photoluminescence blueshift on N concentration has provided extra information on the intrinsic properties of the GaInNAs/GaAs material system. …

Effects of rapid thermal annealing on the optical properties of low-loss 1.3μm GaInNAs∕GaAs saturable Bragg reflectors

2004

We report studies of the effect of rapid thermal annealing (RTA) on the optical properties of a low-loss 1.3 mum saturable Bragg reflector (SBR), consisting of a GaInNAs/GaAs single quantum well embedded in an AlAs/GaAs Bragg reflector grown monolithically on a GaAs substrate. RTA gives rise to a blueshift of the photoluminescence (PL) peak (and therefore of the excitonic absorption peak) and an enhancement of PL intensity, while the reflectivity properties including peak reflectivity and bandwidth are not degraded. Temperature dependent photoluminescence measurements show that the RTA-induced blueshift of photoluminescence consists of two components: one originating from the increase of op…

<title>Hardening in LiF, induced by fast Kr and Ni ions, and recovery of the structure and properties under annealing</title>

2005

The recovery of optical and mechanical properties of LiF crystals irradiated with 790 MeV 78Kr and 640 MeV 58Ni ions at 10l2 ions/cm2 under annealing at temperatures up to 810 K is investigated. The optical absorbance and depth profiles of hardness before and after annealing were measured. A marked recovery of hardness and change in the optical absorption spectra were observed at temperatures above 520-530 K. An activation energy of 0.15±0.02eV, which is close to that for the thermal migration of H centers, is obtained from the annealing data. The results indicate a significant role of the H-center aggregates in the hardening and annealing processes. The maximum hardening is created and the…

Electronic Absorption Spectra of HXeCl, HXeBr, HXeI, and HXeCN in Xe Matrix

2000

The electronic UV absorption spectra of thermal reaction products H−Xe−Y (Y= Cl, Br, I, or CN) have been measured in solid Xe at 12 K. The spectra are obtained after the annealing of an extensively...

Photochemical generation of E′ centres from Si–H in amorphous SiO2under pulsed ultraviolet laser radiation

2006

In situ optical absorption spectroscopy was used to study the generation of E' centres () in amorphous SiO2 occurring by photo-induced breaking of Si–H groups under 4.7 eV pulsed laser radiation. The dependence on laser intensity of the defect generation rate is consistent with a two-photon mechanism for Si–H rupture, while the growth and saturation of the defects are conditioned by their concurrent annealing due to a reaction with mobile hydrogen arising from the same precursor. A rate equation is proposed to model the kinetics of the defects and is tested on experimental data.

Some aspects of the solid state physics of yellow arsenic

1996

Effects of post-growth annealing on structural and compositional properties of the Co2Cr0.6Fe0.4Al surface and its relevance for the surface electron…

2009

In this study we investigate the influence of post-growth annealing on different Co2Cr0.6Fe0.4Al samples. We find strong changes in the geometric surface structure as well as in the element specific concentrations during the annealing process. These irreversible changes go in hand with characteristic changes in the electron spin polarization (ESP) at the surface: as observed in Cinchetti et al (2007 J. Phys. D: Appl. Phys. 40 1544), the iron buffered sample shows the largest spin polarization at the Fermi level. The latter remains positive as a consequence of the reduced density of states for the minority carriers due to the predicted minority gap, which can be clearly seen for all samples …

Influence of initial treatments of aluminium on the morphological features of electrochemically formed alumina membranes

2003

Abstract The fabrication of alumina membranes by electrochemical oxidation of annealed aluminium was investigated. Porous layers were grown in 0.4 M H3PO4 at −1 and 5 °C at different anodising times. The morphology of the outer surface was found to be dependent on temperature and charge density, with both determining the extent of chemical dissolution of the anodic oxide. The inner-surface morphology was found to depend on the applied voltage only. The chemical dissolution rate of anodic oxide grown on annealed aluminium was found to be lower than that formed on unannealed aluminium under otherwise identical conditions. Such a difference in behaviour is explained in terms of a higher finish…