APR Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

Search Volume | RSS Feeds RSS

Applied Physics Reviews — 2010

back to top
RSS Feeds

Superconducting spintronics: Spin-polarized transport in superconducting junctions with ferromagnetic semiconducting contact

Y. C. Tao and J. G. Hu

J. Appl. Phys. 107, 041101 (2010); http://dx.doi.org/10.1063/1.3318287 (13 pages)

Online Publication Date: 25 February 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Superconducting spintronics is one of the most attractive subjects of spintronics. This article reviews superconducting spintronics based on the superconducting junctions with ferromagnetic semiconducting contact. The authors summarize recent theoretical developments with an emphasis on the interplay between ferromagnetic semiconductor (FS) and superconductor (SC). It is found that the spin-polarized transport in the superconducting junctions exhibits a rich dependence on hole types of FS, mismatches in the effective mass and Fermi velocity of holes between the FS and SC, as well as strengths of potential scattering at the interface. These systems have great intrinsic scientific importance and potential device applications including signal processing and general purpose computing.
Show PACS
74.45.+c Proximity effects; Andreev reflection; SN and SNS junctions
85.75.-d Magnetoelectronics; spintronics: devices exploiting spin polarized transport or integrated magnetic fields
72.25.Mk Spin transport through interfaces
72.25.Dc Spin polarized transport in semiconductors
75.50.Dd Nonmetallic ferromagnetic materials
75.50.Pp Magnetic semiconductors

Localized heating induced chemical vapor deposition for one-dimensional nanostructure synthesis

Brian D. Sosnowchik, Liwei Lin, and Ongi Englander

J. Appl. Phys. 107, 051101 (2010); http://dx.doi.org/10.1063/1.3304835 (14 pages)

Online Publication Date: 5 March 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Localized heating has emerged as a viable technique for the site specific synthesis of one-dimensional (1D) nanostructures. By localizing the heat source, the extent of chemical vapor deposition synthesis reactions can be confined to well-defined, microscale regions. Resistive heating has been extensively used to realize highly localized regions of elevated temperature while maintaining a microelectronics-compatible thermal environment elsewhere. Other localized heating methods are being pursued as well. Overall, the approach is simple, flexible, and robust, and offers unique opportunities in 1D nanostructure synthesis, characterization, and integration. Herein, the recent progress of these techniques is reviewed and discussed.
Show PACS
81.07.Bc Nanocrystalline materials
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
07.20.Hy Furnaces; heaters
back to top
RSS Feeds
Author Select

Ion and electron irradiation-induced effects in nanostructured materials

A. V. Krasheninnikov and K. Nordlund

J. Appl. Phys. 107, 071301 (2010); http://dx.doi.org/10.1063/1.3318261 (70 pages)

Online Publication Date: 6 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A common misconception is that the irradiation of solids with energetic electrons and ions has exclusively detrimental effects on the properties of target materials. In addition to the well-known cases of doping of bulk semiconductors and ion beam nitriding of steels, recent experiments show that irradiation can also have beneficial effects on nanostructured systems. Electron or ion beams may serve as tools to synthesize nanoclusters and nanowires, change their morphology in a controllable manner, and tailor their mechanical, electronic, and even magnetic properties. Harnessing irradiation as a tool for modifying material properties at the nanoscale requires having the full microscopic picture of defect production and annealing in nanotargets. In this article, we review recent progress in the understanding of effects of irradiation on various zero-dimensional and one-dimensional nanoscale systems, such as semiconductor and metal nanoclusters and nanowires, nanotubes, and fullerenes. We also consider the two-dimensional nanosystem graphene due to its similarity with carbon nanotubes. We dwell on both theoretical and experimental results and discuss at length not only the physics behind irradiation effects in nanostructures but also the technical applicability of irradiation for the engineering of nanosystems.
Show PACS
61.80.Jh Ion radiation effects
61.80.Fe Electron and positron radiation effects
61.48.-c Structure of fullerenes and related hollow and planar molecular structures
61.46.Df Structure of nanocrystals and nanoparticles ("colloidal" quantum dots but not gate-isolated embedded quantum dots)
61.46.Km Structure of nanowires and nanorods (long, free or loosely attached, quantum wires and quantum rods, but not gate-isolated embedded quantum wires)
61.46.Fg Nanotubes
61.82.Rx Nanocrystalline materials
back to top
RSS Feeds

Physics of ice friction

Anne-Marie Kietzig, Savvas G. Hatzikiriakos, and Peter Englezos

J. Appl. Phys. 107, 081101 (2010); http://dx.doi.org/10.1063/1.3340792 (15 pages)

Online Publication Date: 26 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Although the study of friction has a long history, ice friction has only been investigated during the last century. The basic physical concepts underlying the different friction regimes, such as boundary, mixed, and hydrodynamic friction are also relevant to ice friction. However, these friction regimes must be described with respect to the thickness of the lubricating liquidlike layer on ice. In this review the state of knowledge on the physics of ice friction is discussed. Surface melting theories are introduced. These theories attempt to explain the existence and nature of the liquidlike surface layer on ice at any temperature and without any load applied. Pressure melting, as the long-time explanation for the ease of ice friction, is discussed, together with the prevailing theory of frictional heating. The various laboratory setups for ice friction measurements are presented as well as their advantages and disadvantages. The individual influence of the different parameters on the coefficient of ice friction is discussed; these include the effects of temperature, sliding velocity, normal force exerted by the sliding object, the contact area between ice and slider, relative humidity, and also properties of the slider material such as surface roughness, surface structure, wettability, and thermal conductivity. Finally, the most important ice friction models based on the frictional heating theory are briefly introduced and research directions on the subject of ice friction are discussed.
Show PACS
62.20.Qp Friction, tribology, and hardness
64.70.dj Melting of specific substances
68.08.Bc Wetting
68.35.B- Structure of clean surfaces (and surface reconstruction)

Addendum to “Fundamental questions relating to ion conduction in disordered solids”

J. Ross Macdonald

J. Appl. Phys. 107, 101101 (2010); http://dx.doi.org/10.1063/1.3359703 (9 pages)

Online Publication Date: 20 May 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The extensive review cited in the title discusses “a number of basic scientific questions relating to ion conduction in homogeneously disordered solids” [J. C. Dyre et al., Rep. Prog. Phys. 72, 046501 (2009)]. Although it suggests answers to some of the questions raised, its main purpose is “to draw attention to the fact that this field of research still presents several fundamental challenges.” This work succeeds admirably in that goal, but it does not contain reference to and discussion of some relevant published work related to the fundamental questions it discusses. It is therefore the purpose of this work to add additional information about some of these subjects, including new insights about the Barton, Nakajima, and Namikawa relation. Although most of this information is based on published papers, its omission from the cited review is an indication that it is not widely known and is therefore worth discussing.
Show PACS
66.30.H- Self-diffusion and ionic conduction in nonmetals
99.10.Qr Addenda
77.22.Ch Permittivity (dielectric function)
66.30.Dn Theory of diffusion and ionic conduction in solids

Review of terahertz and subterahertz wireless communications

John Federici and Lothar Moeller

J. Appl. Phys. 107, 111101 (2010); http://dx.doi.org/10.1063/1.3386413 (22 pages)

Online Publication Date: 9 June 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
According to Edholm’s law, the demand for point-to-point bandwidth in wireless short-range communications has doubled every 18 months over the last 25 years. It can be predicted that data rates of around 5–10 Gb/s will be required in ten years. In order to achieve 10 Gb/s data rates, the carrier frequencies need to be increased beyond 100 GHz. Over the past ten years, several groups have considered the prospects of using sub-terahertz (THz) and THz waves (100–2000 GHz) as a means to transmit data wirelessly. Some of the reported advantages of THz communications links are inherently higher bandwidth compared to millimeter wave links, less susceptibility to scintillation effects than infrared wireless links, and the ability to use THz links for secure communications. Our goal of this paper is to provide a comprehensive review of wireless sub-THz and THz communications.
Show PACS
84.40.Ua Telecommunications: signal transmission and processing; communication satellites
back to top
RSS Feeds

A thermodynamic analysis of native point defect and dopant solubilities in zinc-blende III–V semiconductors

D. T. J. Hurle

J. Appl. Phys. 107, 121301 (2010); http://dx.doi.org/10.1063/1.3386412 (47 pages)

Online Publication Date: 21 June 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A thermodynamic model is used to analyze available experimental data relevant to point defects in the binary zinc-blende III–V compounds (Ga,In)-(P,As,Sb). The important point defects and their complexes in each of the materials are identified and included in the model. Essentially all of the available experimental data on dopant solubility, crystal density, and lattice parameter of melt and solution grown crystals and epilayers are reproduced by the model. It extends an earlier study [Hurle, J. Appl. Phys. 85, 6957 (1999)] devoted solely to GaAs. Values for the enthalpy and entropy of formation of both native and dopant related point defects are obtained by fitting to experimental data. In undoped material, vacancies, and interstitials on the Group V sublattice dominate in the vicinity of the melting point (MP) in both the phosphides and arsenides, whereas, in the antimonides, vacancies on both sublattices dominate. The calculated concentrations of the native point defects are used to construct the solidus curves of all the compounds. The charged native point defect concentrations at the MP in four of the six materials are significantly higher than their intrinsic carrier concentrations. Thus the usually assumed high temperature “intrinsic” electroneutrality condition for undoped material (n = p) is not valid for these materials. In GaSb, the GaSb antisite defect appears to be grown-in from the melt. This contrasts with the AsGa defect in GaAs for which the concentration grown-in at the MP is negligibly small. Compensation of donor-doped material by donor-Group III vacancy complexes is shown to exist in all the compounds except InP where Group VI doped crystals are uncompensated and in InSb where there is a lack of experimental data. The annealing effects in n+ GaAs, including lattice superdilation, which were shown in the earlier paper to be due to Group III vacancy undersaturation during cooling, are found to be present also in GaSb and InAs. Results for native point defects are compared with reported “first principles” calculations for GaAs. It is seen that, while there is some accord with experimental findings for low temperature molecular beam epitaxial (MBE) growth, they fail totally to predict the behavior under high temperature growth conditions. The analysis of data on liquid phase epitaxy (LPE) growth of GaAs from Bi solution in the earlier paper has been re-calculated in the light of experimental data that showed that the model used in that paper to represent the Ga–As–Bi phase equilibria was inadequate. An improved model reveals that Ga vacancies exert a greater effect in controlling the extent of the linear range of donor dopant solubility than previously predicted. It has also led to a re-evaluation of the equilibrium EL2 and Ga vacancy concentrations in GaAs during MBE growth under As-rich conditions at low temperatures ( ∼ 500 K). The amended model predicts that the very high concentrations of EL2 and of Ga vacancies observed experimentally are near equilibrium values. The predicted increase in the equilibrium concentrations of these defects at low temperatures results from coulombic attraction between the two defects. At temperatures somewhat lower than 500 K the rate of increase becomes catastrophic.
Show PACS
81.05.Ea III-V semiconductors
68.55.ag Semiconductors
71.55.Eq III-V semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
71.55.Gs II-VI semiconductors
61.72.jd Vacancies
back to top
RSS Feeds
Author Select

Patterned piezo-, pyro-, and ferroelectricity of poled polymer electrets

Xunlin Qiu

J. Appl. Phys. 108, 011101 (2010); http://dx.doi.org/10.1063/1.3457141 (19 pages)

Online Publication Date: 12 July 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Polymers with strong piezo-, pyro-, and ferroelectricity are attractive for a wide range of applications. In particular, semicrystalline ferroelectric polymers are suitable for a large variety of piezo- and pyroelectric transducers or sensors, while amorphous polymers containing chromophore molecules are particularly interesting for photonic devices. Recently, a new class of polymer materials has been added to this family: internally charged cellular space-charge polymer electrets (so-called “ferroelectrets”), whose piezoelectricity can be orders of magnitude higher than that of conventional ferroelectric polymers. Suitable patterning of these materials leads to improved or unusual macroscopic piezo-, pyro-, and ferroelectric or nonlinear optical properties that may be particularly useful for advanced transducer or waveguide applications. In the present paper, the piezo-, pyro-, and ferroelectricity of poled polymers is briefly introduced, an overview on the preparation of polymer electrets with patterned piezo-, pyro-, and ferroelectricity is provided and a survey of selected applications is presented.
Show PACS
81.20.-n Methods of materials synthesis and materials processing
77.65.-j Piezoelectricity and electromechanical effects
77.70.+a Pyroelectric and electrocaloric effects
77.80.-e Ferroelectricity and antiferroelectricity
77.22.-d Dielectric properties of solids and liquids

High aspect ratio silicon etch: A review

Banqiu Wu, Ajay Kumar, and Sharma Pamarthy

J. Appl. Phys. 108, 051101 (2010); http://dx.doi.org/10.1063/1.3474652 (20 pages)

Online Publication Date: 9 September 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
High aspect ratio (HAR) silicon etch is reviewed, including commonly used terms, history, main applications, different technological methods, critical challenges, and main theories of the technologies. Chronologically, HAR silicon etch has been conducted using wet etch in solution, reactive ion etch (RIE) in low density plasma, single-step etch at cryogenic conditions in inductively coupled plasma (ICP) combined with RIE, time-multiplexed deep silicon etch in ICP-RIE configuration reactor, and single-step etch in high density plasma at room or near room temperature. Key specifications are HAR, high etch rate, good trench sidewall profile with smooth surface, low aspect ratio dependent etch, and low etch loading effects. Till now, time-multiplexed etch process is a popular industrial practice but the intrinsic scalloped profile of a time-multiplexed etch process, resulting from alternating between passivation and etch, poses a challenge. Previously, HAR silicon etch was an application associated primarily with microelectromechanical systems. In recent years, through-silicon-via (TSV) etch applications for three-dimensional integrated circuit stacking technology has spurred research and development of this enabling technology. This potential large scale application requires HAR etch with high and stable throughput, controllable profile and surface properties, and low costs.
Show PACS
81.65.Cf Surface cleaning, etching, patterning
81.65.Rv Passivation
back to top
RSS Feeds

Two-dimensional carbon nanostructures: Fundamental properties, synthesis, characterization, and potential applications

Y. H. Wu, T. Yu, and Z. X. Shen

J. Appl. Phys. 108, 071301 (2010); http://dx.doi.org/10.1063/1.3460809 (38 pages)

Online Publication Date: 13 October 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Since its discovery in less than five years ago, graphene has become one of the hottest frontiers in materials science and condensed matter physics, as evidenced by the exponential increase in number of publications in this field. Several reviews have already been published on this topic, focusing on single and multilayer graphene sheets. Here, we review the recent progresses in this field by extending the scope to various types of two-dimensional carbon nanostructures including graphene and free-standing carbon nanowalls/nanosheets. After a brief overview of the electronic properties of graphene, we focus on the synthesis, characterization and potential applications of these carbon nanostructures.
Show PACS
81.07.Bc Nanocrystalline materials
61.48.Gh Structure of graphene
73.22.Pr Electronic structure of graphene
81.05.ue Graphene
back to top
RSS Feeds
Author Select

Review of long period fiber gratings written by CO2 laser

Yiping Wang

J. Appl. Phys. 108, 081101 (2010); http://dx.doi.org/10.1063/1.3493111 (18 pages)

Online Publication Date: 22 October 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This paper presents a systematic review of long period fiber gratings (LPFGs) written by the CO2 laser irradiation technique. First, various fabrication techniques based on CO2 laser irradiations are demonstrated to write LPFGs in different types of optical fibers such as conventional glass fibers, solid-core photonic crystal fibers, and air-core photonic bandgap fibers. Second, possible mechanisms, e.g., residual stress relaxation, glass structure changes, and physical deformation, of refractive index modulations in the CO2-laser-induced LPFGs are analyzed. Third, asymmetrical mode coupling, resulting from single-side laser irradiation, is discussed to understand unique optical properties of the CO2-laser-induced LPFGs. Fourthly, several pretreament and post-treatment techniques are proposed to enhance the efficiency of grating fabrications. Fifthly, sensing applications of the CO2-laser-induced LPFGs are investigated to develop various LPFG-based temperature, strain, bend, torsion, pressure, and biochemical sensors. Finally, communication applications of the CO2-laser-induced LPFGs are investigated to develop various LPFG-based band-rejection filters, gain equalizers, polarizers, and couplers.
Show PACS
42.79.Dj Gratings
42.81.Wg Other fiber-optical devices
42.55.Lt Gas lasers including excimer and metal-vapor lasers
42.60.By Design of specific laser systems
42.82.Cr Fabrication techniques; lithography, pattern transfer
42.70.Qs Photonic bandgap materials
42.25.-p Wave optics

Condensed hydrogen for thermonuclear fusion

S. O. Kucheyev and A. V. Hamza

J. Appl. Phys. 108, 091101 (2010); http://dx.doi.org/10.1063/1.3489943 (28 pages)

Online Publication Date: 3 November 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Inertial confinement fusion (ICF) power, in either pure fusion or fission-fusion hybrid reactors, is a possible solution for future world’s energy demands. Formation of uniform layers of a condensed hydrogen fuel in ICF targets has been a long standing materials physics challenge. Here, we review the progress in this field. After a brief discussion of the major ICF target designs and the basic properties of condensed hydrogens, we review both liquid and solid layering methods, physical mechanisms causing layer nonuniformity, growth of hydrogen single crystals, attempts to prepare amorphous and nanostructured hydrogens, and mechanical deformation behavior. Emphasis is given to current challenges defining future research areas in the field of condensed hydrogens for fusion energy applications.
Show PACS
28.52.-s Fusion reactors
28.52.Fa Materials
28.52.Av Theory, design, and computerized simulation
52.58.-c Other confinement methods

Securing special nuclear material: Recent advances in neutron detection and their role in nonproliferation

R. C. Runkle, A. Bernstein, and P. E. Vanier

J. Appl. Phys. 108, 111101 (2010); http://dx.doi.org/10.1063/1.3503495 (21 pages)

Online Publication Date: 7 December 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Neutron detection is an integral part of the global effort to prevent the proliferation of special nuclear material (SNM). Applications relying on neutron-detection technology range from traditional nuclear nonproliferation objectives, such as safeguarding material and verifying stockpile reductions, to the interdiction of SNM—a goal that has recently risen in priority to a level on par with traditional missions. Large multinational programs targeting interdiction and safeguards have deployed radiation-detection assets across the globe. In parallel with these deployments of commercially available technology, significant research and development has been directed toward the creation of next-generation assets. Neutron-detection technology plays a prominent role because of the capability of neutrons to penetrate materials that readily absorb gamma rays and the unique fission signatures neutrons possess. One particularly acute technology-development challenge results from dwindling supplies of 3He, partially triggered by widespread deployment of high-efficiency systems for portal monitoring. Other emerging missions, such as the desire to detect SNM at greater standoff distances, have also stimulated neutron-detection technology development. In light of these needs, this manuscript reviews the signatures of neutrons emitted by SNM, the principles of neutron detection, and various strategies under investigation for detection in the context of nuclear nonproliferation.
Show PACS
28.41.Bm Fuel elements, preparation, reloading, and reprocessing
28.41.Te Protection systems, safety, radiation monitoring, accidents, and dismantling

High temperature Seebeck coefficient metrology

J. Martin, T. Tritt, and C. Uher

J. Appl. Phys. 108, 121101 (2010); http://dx.doi.org/10.1063/1.3503505 (12 pages)

Online Publication Date: 22 December 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present an overview of the challenges and practices of thermoelectric metrology on bulk materials at high temperature (300 to 1300 K). The Seebeck coefficient, when combined with thermal and electrical conductivity, is an essential property measurement for evaluating the potential performance of novel thermoelectric materials. However, there is some question as to which measurement technique(s) provides the most accurate determination of the Seebeck coefficient at high temperature. This has led to the implementation of nonideal practices that have further complicated the confirmation of reported high ZT materials. To ensure meaningful interlaboratory comparison of data, thermoelectric measurements must be reliable, accurate, and consistent. This article will summarize and compare the relevant measurement techniques and apparatus designs required to effectively manage uncertainty, while also providing a reference resource of previous advances in high temperature thermoelectric metrology.
Show PACS
06.30.Ka Basic electromagnetic quantities
07.20.Ka High-temperature instrumentation; pyrometers
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close