STEP–STEP INTERACTION ENERGY ON Cu(111) VICINAL SURFACES

1999 ◽  
Vol 06 (01) ◽  
pp. 27-34 ◽  
Author(s):  
MARGRET GIESEN ◽  
GEORG SCHULZE ICKING-KONERT
Keyword(s):  
Interaction Potential ◽  
Formation Energy ◽  
Interaction Strength ◽  
Vicinal Surfaces ◽  
Temperature Dependent ◽  
Terrace Width ◽  
Width Distribution ◽  
The Mean ◽  
Step Step ◽  
Step Distance

We have measured the terrace width distribution on copper (111) vicinal surfaces with (100) steps. For all surfaces, the distribution is well fitted by a Gaussian. The width of the Gaussian scales with the mean terrace width L, which is indicative of a repulsive 1/L2 interaction potential between steps. We determine an interaction strength of the potential of 3.2± 0.2 meV per atom length. From the temperature-dependent analysis of the step–step distance distribution, we find a kink formation energy for (100) steps of 0.12± 0.03 eV, which is consistent with previous measurements of the kink energy on copper (100) vicinal surfaces.

Vicinal surfaces: free energy, terrace width distribution and step correlation functions

1999 ◽  
Vol 432 (1-2) ◽  
pp. 139-154 ◽  
Author(s):  
E. Le Goff ◽  
L. Barbier ◽  
L. Masson ◽  
B. Salanon
Keyword(s):  
Free Energy ◽  
Correlation Functions ◽  
Vicinal Surfaces ◽  
Terrace Width ◽  
Width Distribution

Terrace-width distributions on vicinal surfaces: generalized Wigner surmise and extraction of step–step repulsions

2001 ◽  
Vol 175-176 ◽  
pp. 62-68 ◽  
Author(s):  
T.L Einstein ◽  
Howard L Richards ◽  
Saul D Cohen ◽  
O Pierre-Louis ◽  
M Giesen
Keyword(s):  
Vicinal Surfaces ◽  
Terrace Width ◽  
Step Step

scholarly journals Terrace-width distributions and step–step repulsions on vicinal surfaces: symmetries, scaling, simplifications, subtleties, and Schrödinger

2001 ◽  
Vol 493 (1-3) ◽  
pp. 460-474 ◽  
Author(s):  
T.L. Einstein ◽  
Howard L. Richards ◽  
Saul D. Cohen ◽  
O. Pierre-Louis
Keyword(s):  
Vicinal Surfaces ◽  
Terrace Width ◽  
Step Step

scholarly journals Two-term expansion of the ground state one-body density matrix of a mean-field Bose gas

2021 ◽  
Vol 60 (3) ◽  
Author(s):  
Phan Thành Nam ◽  
Marcin Napiórkowski
Keyword(s):  
Density Matrix ◽  
Ground State ◽  
Mean Field ◽  
Interaction Strength ◽  
Bose Gas ◽  
Body Density ◽  
The Mean ◽  
The One ◽  
Mean Field Regime ◽  
Number Of Particles

AbstractWe consider the homogeneous Bose gas on a unit torus in the mean-field regime when the interaction strength is proportional to the inverse of the particle number. In the limit when the number of particles becomes large, we derive a two-term expansion of the one-body density matrix of the ground state. The proof is based on a cubic correction to Bogoliubov’s approximation of the ground state energy and the ground state.

scholarly journals Temperature-Dependent Photoluminescence of ZnO Thin Films Grown on Off-Axis SiC Substrates by APMOCVD

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1035
Author(s):  
Ivan Shtepliuk ◽  
Volodymyr Khranovskyy ◽  
Arsenii Ievtushenko ◽  
Rositsa Yakimova
Keyword(s):  
Optical Properties ◽  
Structural Quality ◽  
Organic Chemical ◽  
Zno Films ◽  
Vicinal Surfaces ◽  
Temperature Dependent ◽  
Step Flow ◽  
Step Flow Growth ◽  
First Time ◽  
Temperature Dependent Photoluminescence

The growth of high-quality ZnO layers with optical properties congruent to those of bulk ZnO is still a great challenge. Here, for the first time, we systematically study the morphology and optical properties of ZnO layers grown on SiC substrates with off-cut angles ranging from 0° to 8° by using the atmospheric pressure meta–organic chemical vapor deposition (APMOCVD) technique. Morphology analysis revealed that the formation of the ZnO films on vicinal surfaces with small off-axis angles (1.4°–3.5°) follows the mixed growth mode: from one side, ZnO nucleation still occurs on wide (0001) terraces, but from another side, step-flow growth becomes more apparent with the off-cut angle increasing. We show for the first time that the off-cut angle of 8° provides conditions for step-flow growth of ZnO, resulting in highly improved growth morphology, respectively structural quality. Temperature-dependent photoluminescence (PL) measurements showed a strong dependence of the excitonic emission on the off-cut angle. The dependences of peak parameters for bound exciton and free exciton emissions on temperature were analyzed. The present results provide a correlation between the structural and optical properties of ZnO on vicinal surfaces and can be utilized for controllable ZnO heteroepitaxy on SiC toward device-quality ZnO epitaxial layers with potential applications in nano-optoelectronics.

Temperature-dependent neutron powder diffraction evidence for splitting of the cationic sites in ferroelectric PbHf0.4Ti0.6O3

1999 ◽  
Vol 55 (1) ◽  
pp. 8-16 ◽  
Author(s):  
C. Muller ◽  
J.-L. Baudour ◽  
V. Madigou ◽  
F. Bouree ◽  
J.-M. Kiat ◽  
...  
Keyword(s):  
Powder Diffraction ◽  
Paraelectric Phase ◽  
Neutron Powder Diffraction ◽  
Cubic Phase ◽  
Temperature Dependent ◽  
Paraelectric Phase Transition ◽  
Type Method ◽  
Space Group ◽  
Atomic Displacements ◽  
The Mean

Temperature-dependent neutron powder diffraction experiments (diffractometer 3T2-LLB, Saclay, France, λ = 1.227 Å) have been performed on the perovskite-like lead hafnate titanate PbHf0.4Ti0.6O3. This compound belongs to the solid solution denoted PHT, which derives from the well known ferroelectric PZT series. It exhibits a ferroelectric-to-paraelectric phase transition around 620 K, between the low-temperature tetragonal phase and the high-temperature cubic phase. The tetragonal structure of the ferroelectric phase has been refined at 10 and 300 K using a Rietveld-type method: space group P4mm with Z = 1; at = 3.999 (1), ct = 4.120 (1) Å, c/a = 1.030, V = 65.89 Å3 at 10 K; at = 4.012 (1) and ct = 4.100 (1) Å, c/a = 1.022, V = 65.99 Å3 at 300 K. The cubic structure of the paraelectric phase has also been refined at 720 K: space group Pm3¯m, Z = 1, ac = 4.046 (1) Å, V = 66.23 Å3. Cation displacements and oxygen-octahedra elongations have been observed as a function of temperature. Evidence for peculiar behaviour associated with the relative shifts of the Hf and Ti atoms (thought until now to be on the same crystallographic site) was found through an anomaly of the mean-square atomic displacements of the Hf/Ti pseudo-nucleus. The PDF Nos for PbHf0.4Ti0.6O3 are 48-49-9 and 48-49-10.

scholarly journals Temperature Dependent Seed Germination of Dalbergia nigra Allem (Leguminosae)

2001 ◽  
Vol 44 (4) ◽  
pp. 401-404 ◽  
Author(s):  
Fernanda G. A. Ferraz-Grande ◽  
Massanori Takaki
Keyword(s):  
Seed Germination ◽  
Endangered Species ◽  
High Temperatures ◽  
Broad Temperature Range ◽  
Optimum Temperature ◽  
Temperature Dependent ◽  
Temperature Range ◽  
Dalbergia Nigra ◽  
The Mean ◽  
Kinetics Of

The germination of endangered species Dalbergia nigra was studied and 30.5° C was found as optimum temperature, although the species presented a broad temperature range where germination occurs and light had no effect. The analysis of kinetics of seed germination confirmed the asynchronized germination below and above the optimum temperature. The light insensitive seed and germination also at high temperatures indicated that D. nigra could occur both in understories and gaps where the mean temperature was high.

Molecular Dynamics of the Properties of Fluid Film Induced by Fluid-Solid Interaction Potential Strength in Wedge Nanochannel

2014 ◽  
Vol 574 ◽  
pp. 133-137
Author(s):  
Yan Jia ◽  
Ping Ge Qu
Keyword(s):  
Molecular Dynamics ◽  
Interaction Potential ◽  
Interaction Strength ◽  
Potential Interaction ◽  
Molecular Dynamics Method ◽  
Fluid Film ◽  
Potential Strength ◽  
The Impact ◽  
Fluid Solid Interaction ◽  
Dynamics Method

Molecular dynamics method is applied to study the influence of fluid-solid interaction potential on the properties of fluid film in wedge nanochannel. The pressure and density are studied for a variety of potential interaction strength between the liquid and the solid. The impact of potential interaction strength between the liquid and the solid on the pressure is limitation. The density alongydirection is affected by the potential interaction strength. As the potential interaction strength is weak, the density of liquids can be affected easily.

Temperature-Dependent Maximum Daily Consumption of Juvenile Salmonids by Northern Squawfish (Ptychocheilus oregonensis) from the Columbia River

1991 ◽  
Vol 48 (12) ◽  
pp. 2491-2498 ◽  
Author(s):  
Steven Vigg ◽  
Craig C. Burley
Keyword(s):  
Simulation Modeling ◽  
Pacific Salmon ◽  
Columbia River ◽  
Temperature Dependent ◽  
Daily Consumption ◽  
Preferred Temperature ◽  
Temperature Range ◽  
Juvenile Pacific Salmon ◽  
The Mean ◽  
Ad Libitum Feeding

Maximum daily consumption rate (Cmax as ration or number) of northern squawfish (Ptychocheilus oregonensis) from the Columbia River increased exponentially as a function of temperature. Predator weight did not explain a significant independent proportion of variation in Cmax. The mean maximum daily ration, determined from replicate ad libitum feeding on juvenile Pacific salmon (Oncorhynchus spp.), was 0.47, 0.70, 3.39, and 4.50 cg∙g−1 at 8.0, 12.5, 17.0, and 21.5 °C, respectively. The corresponding mean daily number eaten was 0.50, 1.17, 4.25, and 7.01 prey per predator at the four increasing temperatures. To quantify the temperature-dependent consumption relation, replicate Cmax data within the preferred temperature range were fitted to exponential and exponential sigmoid models. On the basis of a knowledge of thermal relations of northern squawfish, we combined hypothetical Cmax data at temperature extremes with our mean experimental results to fit an algorithm suitable for use in simulation modeling. Both the generalized gamma and biological-rate (Thornton and Lessem. 1978. Trans. Am. Fish. Soc. 107: 284–287) algorithms were suitable to describe a hypothetical temperature–Cmax model over the entire environmental temperature range of 0–27 °C observed in the Columbia River.

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