This letter shows the ability to perform characterization of the strain field in an aluminium bicrystal subject to plane strain condition induced by micro scale laser shock peening. Intensity contrast method, previous...
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In recent years, there has been an increasing interest in thermal properties of materials. This arises mostly from the practical needs of heat removal and thermal management, which have now become critical issues for ...
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In recent years, there has been an increasing interest in thermal properties of materials. This arises mostly from the practical needs of heat removal and thermal management, which have now become critical issues for the continuing progress in electronic and optoelectronic industries. Another motivation for the study of thermal properties at nanoscale is from a fundamental science perspective. Thermal conductivity of different allotropes of carbon materials span a uniquely large range of values with the highest in graphene and carbon nanotube and the lowest in amorphous or disordered carbon. Here we describe the thermal properties of graphene and carbon-based materials and analyze the prospects of applications of carbon materials in thermal management.
Film chemistry control issues, as well as key properties of polymers synthesized under pulsed plasma conditions, are discussed. Distinctions between pulsed and continuous wave plasmas are examined, particularly as the...
Film chemistry control issues, as well as key properties of polymers synthesized under pulsed plasma conditions, are discussed. Distinctions between pulsed and continuous wave plasmas are examined, particularly as they relate to differences in the energy efficiency of film formation rates and to the range of available power inputs. Film stabilities, with special reference to polymers formed under very low power input conditions, are considered. Finally, selected applications involving use of the inherently high film chemistry controllability made available by the variable duty cycle pulsed plasma technique are described.
Yttrium silicate activated with Ce3+, (Y1−xCex)2SiO5, has been found to be an efficient phosphor that can potentially be used as the blue-emitting component in field emission flat panel displays. This highly refractor...
Yttrium silicate activated with Ce3+, (Y1−xCex)2SiO5, has been found to be an efficient phosphor that can potentially be used as the blue-emitting component in field emission flat panel displays. This highly refractory powder can be synthesized by combustion synthesis, a low cost technique used to fabricate multicomponent oxide powders in a single step process. The effect of activator concentration and post-synthesis annealing was examined on the fluorescent properties. The powders were found to be monoclinic space group P21/c in the as-synthesized state, and transformed to monoclinic space group C2/c after annealing. The maximum luminous emission intensity was reached after a one hour anneal at 1350°C for x=0.0075, with the peak Ce3+ emission wavelength between 420 and 450 nm. When co-doped with Gd3+, no increase in the emission intensity was observed.
Temperature programmed desorption (TPD) studies in ultra high vacuum revealed that diethyltellurium (DETe) and dimethylcadmium (DMCd) adsorb weakly on clean Si(100) and desorb upon heating without decomposing. These p...
Temperature programmed desorption (TPD) studies in ultra high vacuum revealed that diethyltellurium (DETe) and dimethylcadmium (DMCd) adsorb weakly on clean Si(100) and desorb upon heating without decomposing. These precursors adsorb both weakly and strongly on CdTe(111)A, with DMCd exhibiting the stronger interaction with the surface than DETe. Dimethylcadmium partially decomposes to produce Cd adatoms; a large fraction of the excess Cd atoms desorb upon heating. In contrast, DETe desorbs without decomposing, suggesting that the rate limiting step in CdTe MOCVD on CdTe(111)A is surface decomposition of the tellurium alkyl.
Garnet phosphors have potential for use in field emission displays (FEDs). Greenemitting Gd3Ga5O12:Tb (GGG:Tb) and Y3Al5O12:Tb (YAG:Tb) are possible alternatives to ZnO:Zn, because of their excellent resistance to bur...
Garnet phosphors have potential for use in field emission displays (FEDs). Greenemitting Gd3Ga5O12:Tb (GGG:Tb) and Y3Al5O12:Tb (YAG:Tb) are possible alternatives to ZnO:Zn, because of their excellent resistance to burn, low-voltage efficiency, (3.5 lm/W from GGG:Tb at 800 V), and saturation resistance at high power densities. Hydrothermal and combustion synthesis techniques were employed to improve the low-voltage efficiency of YAG:Tb, and Y3Ga5O12:Tb (YGG:Tb). Synthetic technique did not affect low-voltage (100-1000 V) efficiency, but affected the particle size, morphology, and bum resistance. The small particle size phosphors obtained via hydrothermal (<1 µm) and combustion reactions (<1 µm) would benefit projection TV, high-definition TV (HDTV), and heads-up displays (HUDs), where smaller pixel sizes are required for high resolution.
作者：
Alexander A. BalandinNano-Device Laboratory
Department of Electrical Engineering and Materials Science and Engineering Program Bourns College of Engineering University of California Riverside Riverside CA USA
As the electronic industry moves towards few-nanometer-scale CMOS and 3D IC designs thermal management becomes crucially important for achieving high performance and reliability of advanced electronic chips. One appro...
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As the electronic industry moves towards few-nanometer-scale CMOS and 3D IC designs thermal management becomes crucially important for achieving high performance and reliability of advanced electronic chips. One approach for mitigating the self-heating problems is finding materials with very high thermal conductivity, which can be integrated with Si ICs or used as fillers in the next generation of the thermal interface materials (TIMs). In 2008, we discovered that graphene reveals extremely high intrinsic thermal conductivity, which can exceed that of bulk graphite. To measure the thermal conductivity of an object with a thickness of just one atomic layer, we developed an original experimental technique and applied it to graphene flake suspended across trenches in Si wafers. In this technique, the micro-Raman spectrometer performed the function of a thermometer measuring the local temperature rise from the shift in the spectral position of the Raman G peak. We explained the fact that the intrinsic thermal conductivity of graphene can be larger than that of graphite by the fundamental difference in the low-energy phonon transport in 2D graphene and 3D graphite. The extremely high thermal conductivity of “free” suspended graphene does not mean that it will be automatically preserved when graphene is incorporated inside semiconductor chips or composite TIMs. Thermal conductivity of graphene layers depends strongly on their geometrical size, coupling to the adjacent substrate or capping layers, edges roughness and defect concentration. I will overview the experimental and theoretical results for the thermal conductivity evolution of the few-layer graphene (FLG) considering two limiting cases of the phonon transport limited by the intrinsic and extrinsic effects. The use of graphene as interconnects and heat spreaders in advanced 2D and 3D computer chips will also be discussed. The last section of the talk will have a description of the data for graphene TIM materials. W
In view of the extreme toxicity of arsenic on human and other living organism the U.S. Environmental Protection Agency (U.S. EPA) has fixed the maximum contaminant level (MCL) for arsenic as 10 ppb in drinking water. ...
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The effect of hot isostatic pressure processing (HIP) on MnAl films has been compared to vacuum annealing for the purpose of obtaining substantial amounts of tau phase MnAl in films under 200 nm. Films were deposited ...
The effect of hot isostatic pressure processing (HIP) on MnAl films has been compared to vacuum annealing for the purpose of obtaining substantial amounts of tau phase MnAl in films under 200 nm. Films were deposited by dc sputtering from both MnAlNiC an MnAl targets. As-deposited films were nearly amorphous. Post deposition annealing in vacuum produced only small amounts of the ferromagnetic tau-phase in films thinner than 200 *** all instances, regardless of substrate and sputtering target, the use of HIP in place of vacuum annealing increased the degree of crystallinity of the samples when compared to those annealed in vacuum. For the 100 nm samples deposited from the MnAlNiC target, these changes in crystallinity were accompanied by changes in the M-H loops of the samples. MnAlNiC HIP samples had improved magnetic properties compared to those of equal thickness annealed in vacuum. The 100 nm HIP sample sputtered from the MnAl target also showed an increase in moment, though the changes were not as dramatic as those seen in the samples sputtered from the MnAlNiC *** 50 nm films from both targets also showed a change in crystallinity when compared to vacuum annealed samples. These films, unlike the 100 nm films, had ferromagnetic properties that were no better than those of the vacuum annealed samples. This suggests that while the 2 kbar of pressure used in this study assists in the formation of tau-phase in 100 nm films, the appropriate pressure for forming tau-phase in 50 nm films is yet to be determined.
In this paper we present a comprehensive analysis of line tension-driven compositional interface fluctuations in planar lipid bilayer membranes. Our starting point is the advective Cahn-Hilliard equation for the local...
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In this paper we present a comprehensive analysis of line tension-driven compositional interface fluctuations in planar lipid bilayer membranes. Our starting point is the advective Cahn-Hilliard equation for the local lipid composition in symmetric membranes, which explicitly incorporates both advective and diffusive lipid transport processes, and which is coupled to the continuum hydrodynamic equations governing the flow behavior of the membrane and surrounding solvent with finite subphase thickness. In order to extract the interface dynamics from the continuum phase-field formalism, we first derive the appropriate sharp-interface limit equations. We then carry out a linear perturbation analysis for the relaxational dynamics of small-amplitude sinusoidal interface fluctuations to yield the general dispersion relation ωk as a function of perturbation wave number k. The resulting expression incorporates the effects of diffusive and advective lipid transport processes within the membrane, viscous or viscoelastic membrane properties, coupling between membrane and solvent, and inertial effects within the membrane and solvent. It is shown that previously considered scenarios naturally emerge as limiting cases of the general result. Furthermore, we discuss two additional scenarios amenable to analysis, one in which the inertia of the solvent is relevant, and another one in which the membrane displays significant viscoelastic properties. Finally, we numerically evaluate the general dispersion relation for three representative model membrane systems.
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