scholarly journals The influence of the electroneutrality of the metal layer on the plasmon spectrum in "dielectric-metal-dielectric" structures

2019 ◽  
pp. 141-144
Author(s):  
Vitalii Polovyi ◽  
Kostrobiy Petro
Keyword(s):  
Wave Vector ◽  
Metal Layer ◽  
Energy Levels ◽  
Metal Thickness ◽  
Fermi Wave Vector ◽  
Dielectric Structures ◽  
Plasmon Spectrum

This paper proposes a model that takes into account the discretization of the Fermi wave vector and energy levels, as well as the condition of electroneutrality when investigating the influence of metal thickness on the spectrum of SPPs waves in heterogeneous dielectric-metal-dielectric structures.

scholarly journals Influence of the electroneutrality of a metal layer on the plasmon spectrum in dielectric-metal-dielectric structures

2019 ◽  
Vol 6 (2) ◽  
pp. 297-303 ◽  
Author(s):  
P. P. Kostrobij ◽  
◽  
B. M. Markovych ◽  
V. Ye. Polovyi ◽  
◽  
...  
Keyword(s):  
Metal Layer ◽  
Dielectric Structures ◽  
Plasmon Spectrum

scholarly journals Effect of Metal Thickness on the Sensitivity of Crack-Based Sensors

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2872 ◽  
Author(s):  
Eunhan Lee ◽  
Taewi Kim ◽  
Heeseong Suh ◽  
Minho Kim ◽  
Peter Pikhitsa ◽  
...  
Keyword(s):  
American Sign Language ◽  
High Performance ◽  
Metal Layer ◽  
High Sensitivity ◽  
Human Motion ◽  
Motion Detector ◽  
Metal Thickness ◽  
Mechanical Crack ◽  
Pet Film ◽  
The Relationship

Among many attempts to make a decent human motion detector in various engineering fields, a mechanical crack-based sensor that deliberately generates and uses nano-scale cracks on a metal deposited thin film is gaining attention for its high sensitivity. While the metal layer of the sensor must be responsible for its high performance, its effects have not received much academic interest. In this paper, we studied the relationship between the thickness of the metal layer and the characteristics of the sensor by depositing a few nanometers of chromium (Cr) and gold (Au) on the PET film. We found that the sensitivity of the crack sensor improves/increases under the following conditions: (1) when Au is thin and Cr is thick; and (2) when the ratio of Au is lower than that of Cr, which also increases the transmittance of the sensor, along with its sensitivity. As we only need a small amount of Au to achieve high sensitivity of the sensor, we have suggested more efficient and economical fabrication methods. With this crack-based sensor, we were able to successfully detect finger motions and to distinguish various signs of American Sign Language (ASL).

scholarly journals Dependence of the magnetic properties of MnGaN epitaxial layers on external electrical field

2009 ◽  
Vol 7 (2) ◽  
pp. 175-178 ◽  
Author(s):  
Dimiter Alexandrov
Keyword(s):  
Magnetic Properties ◽  
Band Gap ◽  
Energy Band ◽  
Field Effect ◽  
Metal Layer ◽  
Energy Levels ◽  
Epitaxial Layers ◽  
Energy Band Gap ◽  
Electrical Field ◽  
External Electrical Field

AbstractInvestigation of the magnetic properties of MnGaN epitaxial layers as a function of external electrical field was performed on the basis of field effect structure. The structure included substrate of n-type GaN, epitaxial layer of n-type MnxGa1-xN, dielectric layer and metal layer acting as field effect device gate. Each Mn atom in MnxGa1-xN contributes 4 net spins due to the electrons occupying energy levels 4F, 4D, 4P and 4G belonging to 3d orbital, and these levels are in the energy band gap and in the top of the valence band of MnxGa1-xN. The position of the Fermi level is determined to be in the energy band gap of the layer of GaN and to be above the level 4F in the layer of MnxGa1-xN. In this way application of external negative voltage on the gate causes change in the number of electrons contributing net spins and the saturation magnetization Msat of MnxGa1-xN changes as well. It was found that Msat changes in the range 1.15 × 10−3–0.7 × 10−3 A μm−1 if the external voltage changes in the interval 0–−5V. The application of this structure for the design of spintronic devices is discussed in this paper.

Effects of Metal Thickness on Bonding Strength in Bonded Dissimilar Materials

2014 ◽  
Author(s):  
Masayoshi Tateno ◽  
Takahiro Miura
Keyword(s):  
Residual Stress ◽  
Tensile Strength ◽  
Stress Distribution ◽  
Metal Layer ◽  
Thin Metal ◽  
Joint System ◽  
Thin Metal Layer ◽  
Metal Thickness ◽  
Metal Joint ◽  
Two Stages

This study provides effects of metal thickness on bonding tensile strength of ceramic to metal joint based on numerical and experimental analyses. Thermal elastoplastic FEA was carried out to clarify effects of the metal side thickness on the stress distribution near the edge of the interface on ceramic side by changing metal side thickness each bonded silicon nitride to nickel joint system. It was confirmed the stress distribution on the ceramic of the joint system depends on the metal side thickness based on the FEM results. Decreasing of metal thickness reduces the intensity of the stress near the edge of the interface on ceramics side. It can be effective for reduction of the residual stress near the edge of the interface to use thin metal layer in the ceramic to metal joint. Reduction effects on the residual stress were confirmed by using two stages of bonding processing. This process used in this experiment consists of two stages, first bonding process as the ceramic are bonded to thin layer metal at high temperature, and secondary process as thick metal are bonded to the thin metal layer of the joint specimen at lower temperature than first stage. The bonding tensile strength of the joint specimens manufactured from the two stages bonding processe was evaluated experimentally. It appears that setting a ratio of metal thickness to length of the interface to approximate tm/W=0.08 achieves maximum bonding tensile strength. Effects of metal thickness on bonding tensile strength of ceramic to metal joint are confirmed based on numerical and experimental results.

scholarly journals Doped Kondo chain, a heavy Luttinger liquid

2018 ◽  
Vol 115 (20) ◽  
pp. 5140-5144 ◽  
Author(s):  
Ilia Khait ◽  
Patrick Azaria ◽  
Claudius Hubig ◽  
Ulrich Schollwöck ◽  
Assa Auerbach
Keyword(s):  
Conduction Band ◽  
Power Law ◽  
Wave Vector ◽  
Luttinger Liquid ◽  
Magnetic Ordering ◽  
Kondo Lattice ◽  
Low Energy ◽  
Fermi Velocity ◽  
Large N ◽  
Fermi Wave Vector

The doped 1D Kondo Lattice describes complex competition between itinerant and magnetic ordering. The numerically computed wave vector-dependent charge and spin susceptibilities give insights into its low-energy properties. Similar to the prediction of the large N approximation, gapless spin and charge modes appear at the large Fermi wave vector. The highly suppressed spin velocity is a manifestation of “heavy” Luttinger liquid quasiparticles. A low-energy hybridization gap is detected at the small (conduction band) Fermi wave vector. In contrast to the exponential suppression of the Fermi velocity in the large-N approximation, we fit the spin velocity by a density-dependent power law of the Kondo coupling. The differences between the large-N theory and our numerical results are associated with the emergent magnetic Ruderman–Kittel–Kasuya–Yosida interactions.

Bonding Temperature Condition Dependence of Strength Improvement Effect by Decrease of Metal Thickness in Ceramic to Metal Joint System

2016 ◽  
Author(s):  
Masayoshi Tateno ◽  
Takashi Tominaga
Keyword(s):  
Residual Stress ◽  
Metal Layer ◽  
Bonding Temperature ◽  
Thin Metal ◽  
Joint System ◽  
Temperature Conditions ◽  
Metal Thickness ◽  
Metal Joint ◽  
Two Stages ◽  
Secondary Bonding

This study provides effects of bonding temperature conditions on practical strength in ceramic to metal joint system made by two stages bonding process. Ceramic to metal joint system is required to reduce the residual stress near the edge of the interface and to improve bonding strength. The two stages bonding process, which was proposed in PVP2015-45822, can be a useful method to prevent the residual stress from increasing. This process consists of two stages, the first bonding process defined as a ceramic is bonded to thin metal layer at high temperature and the secondary process defined as a thick metal is bonded to the thin metal layer of the joint at lower temperature. It is necessary to provide effects of thickness of thin metal layer on the practical bonding strength in various combinations of the first and the secondary bonding temperature conditions. Past experimental results showed the practical bonding strength would be dominated by the residual stress near the edge of the interface between the thin metal layer and the ceramic. The residual stress can be associated with the first and/or the secondary bonding temperature conditions. Setting the optimum metal thickness improves the bonding strength independent of the bonding temperature conditions in the limited conditions. This paper provided dependence of the optimum metal layer thickness on the first and the secondary bonding temperature conditions was clarified experimentally. It also found effective metal thickness, which is capable of strengthening the siliconnitride to nickel joint system, in the combination of the first bonding temperature ranged over from 880°C to 980°C and the secondary bonding temperature ranged over from 600°C to 700°C. It appeared the first bonding temperature and the secondary one are set at the higher, the optimum metal thickness becomes smaller. The result showed that decreasing metal thickness possesses similar effect to decreasing bonding temperature for reducing the thermal residual stress. Reducing the residual stress is capable of strengthening the part of the edge of the interface on the ceramic side. Setting the metal layer thinner should be applied for producing the high strength ceramic to metal joint system. The two stages bonding process can contribute to achieve the high strength bonded dissimilar materials by setting the optimum thin metal thickness.

A NEW APPROACH TO THE STUDY OF NUCLEAR MATTER

1994 ◽  
Vol 03 (02) ◽  
pp. 715-733 ◽  
Author(s):  
D.N. TRIPATHY ◽  
L.K. MISHRA
Keyword(s):  
Nuclear Matter ◽  
Wave Vector ◽  
Compression Modulus ◽  
Present Theory ◽  
Density Fluctuations ◽  
Present Calculation ◽  
Correct Result ◽  
Zero Sound ◽  
Sound Mode ◽  
Fermi Wave Vector

By invoking the existence of the zero-sound mode we have succeeded in generalizing the Bohm-Pines method, for the collective description of the interparticle interactions in a dense electron gas, to calculate the binding energy per nucleon in the ground state of a nuclear matter. The present calculation gives rise to a saturation Fermi wave vector kFO=1.74 fm−1, which is larger than the mostly accepted value of 1.43 fm−1. Our calculated result for the velocity of the zero-sound mode is found to be well-agreeable with those of other theories. It is further seen that there is an instability in the nuclear matter, with respect to long wavelength density fluctuations, in the low density region n≤0.78n0, n0 being the saturation nuclear density. From the present theory, we obtain a compression modulus K=116.7 MeV at the saturation density, which is smaller than the well-known result (210±30) MeV. However, by adjusting the value of the effective mass, M*, of the nucleon, we are able to reproduce the correct result for the compression modulus. Such a value of M* is found to be greater than the bare nucleon mass M. From the present theory, we obtain the energy of the monopole resonance Eph=32.38 MeV, which agrees reasonably well with the experimental data for heavy nuclei. By lowering the value of the saturation Fermi wave vector, we observe a decrease in the value of the compression modulus, which is just the opposite to the results of other theoretical calculations.

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