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

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

30 May 2011

Volume 98, Issue 22, Articles (22xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 98, 223101 (2011); http://dx.doi.org/10.1063/1.3595266 (3 pages)

Takahiro Ohori, Yasuhide Ohno, Kenzo Maehashi, Koichi Inoue, Yutaka Hayashi, and Kazuhiko Matsumoto
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Multidirectional surface-wave splitters

Yong Jin Zhou and Tie Jun Cui

Appl. Phys. Lett. 98, 221901 (2011); http://dx.doi.org/10.1063/1.3595281 (3 pages) | Cited 5 times

Online Publication Date: 31 May 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We propose a multidirectional surface-wave splitter excited by a cylindrical wire. Such a splitter could function as a plasmonic wavelength-division multiplexer, since electromagnetic waves at the designed frequencies will be confined and guided along different multiple grating structures that are placed around the cylindrical wire. The experimental verification of the proposed splitter has been implemented in the microwave frequencies. The measurement results have excellent agreements to the full-wave simulations to show the good performance of the splitter. We also propose and simulate a multidirectional surface-wave splitter in the terahertz frequency to validate the concept.
Show PACS
42.79.Fm Reflectors, beam splitters, and deflectors
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)
78.66.Bz Metals and metallic alloys
78.68.+m Optical properties of surfaces
42.79.Dj Gratings

Interface engineering of high-Mg-content MgZnO/BeO/Si for p-n heterojunction solar-blind ultraviolet photodetectors

H. L. Liang, Z. X. Mei, Q. H. Zhang, L. Gu, S. Liang, Y. N. Hou, D. Q. Ye, C. Z. Gu, R. C. Yu, and X. L. Du

Appl. Phys. Lett. 98, 221902 (2011); http://dx.doi.org/10.1063/1.3595342 (3 pages) | Cited 4 times

Online Publication Date: 31 May 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
High-quality wurtzite MgZnO film was deposited on Si(111) substrate via a delicate interface engineering using BeO, by which solar-blind ultraviolet photodetectors were fabricated on the n-MgZnO(0001)/p-Si(111) heterojunction. A thin Be layer was deposited on clean Si surface with subsequent in situ oxidation processes, which provides an excellent template for high-Mg-content MgZnO growth. The interface controlling significantly improves the device performance, as the photodetector demonstrates a sharp cutoff wavelength at 280 nm, consistent with the optical band gap of the epilayer. Our experimental results promise potential applications of this technique in integration of solar-blind ultraviolet optoelectronic device with Si microelectronic technologies.
Show PACS
81.05.Dz II-VI semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
85.60.Gz Photodetectors (including infrared and CCD detectors)
68.55.ag Semiconductors
73.40.Lq Other semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
78.66.Hf II-VI semiconductors

Another kinetic mechanism of stabilizing multiple-layer surface steps

Ruoxin Zhang and Hanchen Huang

Appl. Phys. Lett. 98, 221903 (2011); http://dx.doi.org/10.1063/1.3595938 (3 pages) | Cited 4 times

Online Publication Date: 31 May 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This letter reports that a large three-dimensional Ehrlich–Schwoebel (3D ES) barrier kinetically stabilizes multiple-layer surface steps. The report is based on (1+1)D lattice kinetic Monte Carlo simulations of Cu{111} surfaces. The larger 3D ES barrier leads to slower diffusion over multiple-layer steps, thereby slower dissociation and higher stability. The higher stability of multiple-layer surface steps, in turn, facilitates the operation of the 3D ES barrier; a positive feedback relationship. The mechanism of kinetically stabilizing multiple-layer surface steps allows another way of controlling surface morphology to promote the growth of either nanorods or smooth thin films.
Show PACS
68.47.Pe Langmuir-Blodgett films on solids; polymers on surfaces; biological molecules on surfaces
68.35.bd Metals and alloys
66.30.Fq Self-diffusion in metals, semimetals, and alloys

Thermal conductivity as a metric for the crystalline quality of SrTiO3 epitaxial layers

Dong-Wook Oh, Jayakanth Ravichandran, Chen-Wei Liang, Wolter Siemons, Bharat Jalan, Charles M. Brooks, Mark Huijben, Darrell G. Schlom, Susanne Stemmer, Lane W. Martin, Arun Majumdar, Ramamoorthy Ramesh, and David G. Cahill

Appl. Phys. Lett. 98, 221904 (2011); http://dx.doi.org/10.1063/1.3579993 (3 pages) | Cited 9 times

Online Publication Date: 31 May 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Measurements of thermal conductivity Λ by time-domain thermoreflectance in the temperature range 100<T<300 K are used to characterize the crystalline quality of epitaxial layers of a prototypical oxide, SrTiO3. Twenty samples from five institutions using two growth techniques, molecular beam epitaxy and pulsed laser deposition (PLD), were analyzed. Optimized growth conditions produce layers with Λ comparable to bulk single crystals. Many PLD layers, particularly those that use ceramics as the target material, show surprisingly low Λ. For homoepitaxial layers, the decrease in Λ created by point defects correlates well with the expansion of the lattice parameter in the direction normal to the surface.
Show PACS
66.70.Lm Other systems such as ionic crystals, molecular crystals, nanotubes, etc.
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.55.aj Insulators
81.15.Fg Pulsed laser ablation deposition
61.72.J- Point defects and defect clusters
61.66.Fn Inorganic compounds

Size-dependent photochromism-based holographic storage of Ag/TiO2 nanocomposite film

Runyuan Han, Xintong Zhang, Lingling Wang, Rui Dai, and Yichun Liu

Appl. Phys. Lett. 98, 221905 (2011); http://dx.doi.org/10.1063/1.3595399 (3 pages) | Cited 1 time

Online Publication Date: 2 June 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The influence of size distribution of Ag nanoparticles (NPs) on photochromic behavior and holographic storage dynamics of Ag/TiO2 films was investigated using a 532 nm laser as excitation source and recording beams, respectively. Experimental results suggest that small Ag NPs are subject to easier photoinduced oxidative dissolution than large Ag NPs under the 532 nm excitation, and contribute to the rapid growth of holographic grating in the initial stage. These observations were discussed in terms of size-dependent silver redox potential influencing both interfacial electron transfer among Ag NPs and TiO2 matrix and subsequent dissolution of Ag NPs, as well as surface plasmon resonance absorption property of Ag NPs also related to their size distribution.
Show PACS
42.70.Ln Holographic recording materials; optical storage media
42.79.Vb Optical storage systems, optical disks
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)
73.22.Lp Collective excitations
78.68.+m Optical properties of surfaces
42.40.Eq Holographic optical elements; holographic gratings
42.40.My Applications

Dislocation cross-slip in GaN single crystals under nanoindentation

J. Huang, K. Xu, X. J. Gong, J. F. Wang, Y. M. Fan, J. Q. Liu, X. H. Zeng, G. Q. Ren, T. F. Zhou, and H. Yang

Appl. Phys. Lett. 98, 221906 (2011); http://dx.doi.org/10.1063/1.3593381 (3 pages) | Cited 5 times

Online Publication Date: 2 June 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The dislocation multiplication and movement mechanism in GaN single crystals has been studied using nanoindentation and cathodoluminescence. Dislocation loops can multiply and move from plane to plane by cross-slip, thus producing a wide plastic deformation in GaN during indentation. This mechanism is further supported by the remarkable movement of indentation induced dislocations during annealing. Furthermore, the so-called pop-in events, in which the indenter suddenly enters deeper into the material without the application of any additional force, can be better understood by considering the cross-slip mechanism.
Show PACS
61.72.Hh Indirect evidence of dislocations and other defects (resistivity, slip, creep, strains, internal friction, EPR, NMR, etc.)
81.40.Np Fatigue, corrosion fatigue, embrittlement, cracking, fracture, and failure
62.20.me Fatigue
78.60.Hk Cathodoluminescence, ionoluminescence

Formation of Zn defects in willemite-type Zn2GeO4 during supercooled liquid-crystal phase transition

Yoshihiro Takahashi, Masataka Ando, Rie Ihara, and Takumi Fujiwara

Appl. Phys. Lett. 98, 221907 (2011); http://dx.doi.org/10.1063/1.3597300 (3 pages) | Cited 3 times

Online Publication Date: 3 June 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This letter elucidates the formation mechanism of interstitial Zn defects in wide band-gap semiconductive willemite-type Zn2GeO4 via nanocrystallization in a zincogermanate glass. The results of time-development structural observations suggest that Zn2GeO4 nanocrystals precipitate in the nanometric Zn-condensed region, which occurs prior to nanocrystallization. The Zn-condensed environment probably promotes the capture of Zn ions in the interstitial sites of the Zn2GeO4 structure during the structural ordering of the supercooled liquid phase. The Zn-condensation mechanism is also discussed.
Show PACS
61.72.jj Interstitials
64.70.dg Crystallization of specific substances
64.70.mj Experimental studies of liquid crystal transitions
64.70.pp Liquid crystals
64.70.Nd Structural transitions in nanoscale materials
81.16.Pr Micro- and nano-oxidation

First-principles studies of complex hydride YMn2H6 and its synthesis from metal hydride YMn2H4.5

Motoaki Matsuo, Kazutoshi Miwa, Satoshi Semboshi, Hai-Wen Li, Mika Kano, and Shin-ichi Orimo

Appl. Phys. Lett. 98, 221908 (2011); http://dx.doi.org/10.1063/1.3597363 (3 pages) | Cited 6 times

Online Publication Date: 3 June 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
First-principles calculations were performed for a complex hydride YMn2H6 to investigate its electronic structure and thermodynamic stability. The results indicated that an Y atom and one of two Mn atoms were ionized as Y3+ and Mn2+, respectively, and another Mn atom bound covalently to H atoms to form a [MnH6]5− complex anion. Based on the enthalpy change of −65 kJ/mol estimated from the calculation, we experimentally verified a possible low-pressure synthesis of YMn2H6 from a metal hydride YMn2H4.5. X-ray diffractometry confirmed the formation of YMn2H6 after hydrogenation below 5 MPa, much lower than the previously reported value of 170 MPa.
Show PACS
71.20.Ps Other inorganic compounds
65.40.-b Thermal properties of crystalline solids
71.15.-m Methods of electronic structure calculations

An electroactuation system based on nanofluids

Baoxing Xu, Yu Qiao, Yibing Li, Qulan Zhou, and Xi Chen

Appl. Phys. Lett. 98, 221909 (2011); http://dx.doi.org/10.1063/1.3597367 (3 pages) | Cited 3 times

Online Publication Date: 3 June 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We propose the conceptual design of an electrically controlled actuation system by adjusting the relative hydrophobicity of a nanoporous material/liquid mixture. When the variation in wettability is amplified by the large surface area, a considerable mechanical work is output. The energy density, power density, and efficiency are explored and their variations with pore size, solid phase, and liquid phase are explored. An infiltration experiment on a nanoporous silica system is performed to qualitatively validate these findings.
Show PACS
07.10.Cm Micromechanical devices and systems
47.85.Np Fluidics

Theoretical insight of adsorption cooling

Anutosh Chakraborty, Kai Choong Leong, Kyaw Thu, Bidyut Baran Saha, and Kim Choon Ng

Appl. Phys. Lett. 98, 221910 (2011); http://dx.doi.org/10.1063/1.3592260 (3 pages) | Cited 4 times

Online Publication Date: 3 June 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This letter proposes and presents a thermodynamic formulation to calculate the energetic performances of an adsorption cooler as a function of pore widths and volumes of solid adsorbents. The simulated results in terms of the coefficient of performance are validated with experimental data. It is found from the present analysis that the performance of an adsorption cooling device is influenced mainly by the physical characteristics of solid adsorbents, and the characteristics energy between the adsorbent-adsorbate systems. The present study confirms that there exists a special type of silica gel having optimal physical characteristics that allows us to obtain the best performance.
Show PACS
68.43.Mn Adsorption kinetics
82.70.Gg Gels and sols
68.35.Md Surface thermodynamics, surface energies
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close