jap banner
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

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

15 Sep 2006

Volume 100, Issue 6, Articles (06xxxx)

Return to All Sections
back to top
RSS Feeds

Increase of water viscosity under the influence of magnetic field

S. A. Ghauri and M. S. Ansari

J. Appl. Phys. 100, 066101 (2006); http://dx.doi.org/10.1063/1.2347702 (2 pages) | Cited 11 times

Online Publication Date: 20 September 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Effect of applied magnetic field on the water viscosity between 298 and 323 K has been investigated. A higher absolute viscosity has been observed in the presence of applied magnetic field compared to no field which has been explained on the basis of stronger hydrogen bonds. The measurement is found to increase consistently at higher temperatures. The relative increase in viscosity Δη/η0 is of the order of 10−3 in a 7.5 kG transverse magnetic field where Δη is the viscosity change compared to the no-field viscosity η0 at a given temperature.
Show PACS
66.20.-d Viscosity of liquids; diffusive momentum transport
47.65.-d Magnetohydrodynamics and electrohydrodynamics

Enhanced electrical characteristics of Au nanoparticles embedded in high-k HfO2 matrix

Jung Yup Yang, Ju Hyung Kim, Won Joon Choi, Young Ho Do, Chae Ok Kim, and Jin Pyo Hong

J. Appl. Phys. 100, 066102 (2006); http://dx.doi.org/10.1063/1.2347703 (3 pages) | Cited 11 times

Online Publication Date: 20 September 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present experimental results for laser-induced Au nanoparticle (NP) embedded in a HfO2 high-k dielectric matrix. Cross-sectional transmission electron microscopy images showed that the Au NPs of 8 nm in diameter were clearly embedded in HfO2 matrix. Capacitance-voltage measurements of Pt/HfO2/Au NPs/HfO2 on p-type Si substrate reliably exhibited metal-oxide-semiconductor behavior with a large flatband shift of 4.7 V. In addition, the charge retention time at room temperature was found to exceed 105 h. This longer time was attributed to the higher electron barrier height via high work function of the Au NP.
Show PACS
73.30.+y Surface double layers, Schottky barriers, and work functions
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
61.46.Df Structure of nanocrystals and nanoparticles ("colloidal" quantum dots but not gate-isolated embedded quantum dots)
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
77.55.-g Dielectric thin films

Experimental verification of the applicability of the homogenization approximation to rough one-dimensional photonic crystals using a holographically fabricated reflection grating

Karlene Rosera Maskaly, Vincent K. S. Hsiao, Alexander N. Cartwright, Paras N. Prasad, P. F. Lloyd, Timothy J. Bunning, and W. Craig Carter

J. Appl. Phys. 100, 066103 (2006); http://dx.doi.org/10.1063/1.2336346 (3 pages) | Cited 4 times

Online Publication Date: 20 September 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The theoretical reflectance spectrum of a one-dimensional photonic crystal with large amounts of interfacial roughness has been calculated using a previously proposed method, and compared to the actual experimental reflectivity of the structure. The photonic crystal was fabricated using a simple and fast method involving the holographic exposure of a liquid crystal/photosensitive prepolymer syrup via the self-interference patterns from two laser beams. The calculated reflectance spectrum for this structure matched the experimental one extremely well, giving very similar reflectivity peak positions and intensities. Slight discrepancies between the two reflectance spectra are attributed to either small variations in the microstructure of the reflection grating beyond that which is captured in the transmission electron micrograph, or the dispersion of the polymer which was not taken into account. These results serve as experimental verification of the theory for rough photonic crystals reported previously.
Show PACS
42.70.Qs Photonic bandgap materials
42.40.Eq Holographic optical elements; holographic gratings
42.40.Kw Holographic interferometry; other holographic techniques
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
82.35.-x Polymers: properties; reactions; polymerization

Trimodal island distribution of Ge nanodots on (001)Si

Jacob Balle, John Lundsgaard Hansen, and Arne Nylandsted Larsen

J. Appl. Phys. 100, 066104 (2006); http://dx.doi.org/10.1063/1.2336508 (3 pages) | Cited 4 times

Online Publication Date: 20 September 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Molecular beam epitaxy (MBE) grown Ge nanodots are found to come in a clear trimodal island distribution of huts, pyramids, and domes when grown on (001)Si at 550°C. The island types appear in this order as Ge coverage increases and for a certain coverage all three types are found to coexist at this growth temperature. Previously Ge nanodots have mostly been divided into huts and domes at growth temperatures below 600°C, or pyramids and domes above 600°C. The {105} faceted pyramidal and elongated huts and the multifaceted domes are well known, but a distinction has not previously been seen between huts and a separate size distribution of similarly {105}-faceted pyramidal nanodots twice the size of huts, at temperatures below 600°C. The 20–25 nm wide huts also appear to be the smallest obtainable self-assembled Ge dots on (001)Si, in accordance with predictions based on Si1−xGex nanodots on (001)Si. They are about a factor of two too large for quantum dot applications.
Show PACS
68.65.Hb Quantum dots (patterned in quantum wells)
81.07.Ta Quantum dots
81.16.Dn Self-assembly
61.46.Hk Nanocrystals
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy

Electromagnetic simulation of terahertz frequency range filters for genetic sensing

C. K. Tiang, J. Cunningham, C. Wood, I. C. Hunter, and A. G. Davies

J. Appl. Phys. 100, 066105 (2006); http://dx.doi.org/10.1063/1.2335601 (3 pages) | Cited 8 times

Online Publication Date: 22 September 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on a numerical study of the sensitivity of electrical terahertz (THz) frequency range passive filters under conditions of dielectric loading. We investigate band-pass filters, ring resonators, and band-stop filters, all of which have been proposed as devices capable of measuring the hybridization state of overlaid DNA films, thereby acting as genetic sensors. The transmission characteristics of these filters are examined when loaded with samples of different relative permittivities and thicknesses, and these results are discussed in the context of recent experimental works. A comparative analysis of the three filter types is performed, and conclusions are drawn on the suitability of the various filters for the analysis of DNA films during genetic testing and other dielectric materials.
Show PACS
87.80.-y Biophysical techniques (research methods)
84.40.Dc Microwave circuits
87.14.G- Nucleic acids
84.30.Vn Filters
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors
07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing

Hysteresis in acoustic properties of ferroelectric relaxor Pb[(Zn1/3Nb2/3)0.955Ti0.045]O3 single crystals studied by Brillouin and dielectric spectroscopies

Jae-Hyeon Ko, Do Han Kim, Seiji Kojima, Wenzhi Chen, and Zuo-Guang Ye

J. Appl. Phys. 100, 066106 (2006); http://dx.doi.org/10.1063/1.2338829 (3 pages) | Cited 12 times

Online Publication Date: 27 September 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Acoustic and dielectric properties of Pb[(Zn1/3Nb2/3)1−xTix]O3 (PZN‐xPT) single crystals with x = 0.045 have been studied by the high-resolution micro-Brillouin scattering and dielectric spectroscopy in a wide temperature range. The softening of the Brillouin shift and the increase of dielectric relaxation time upon cooling indicated the formation of polar nanoregions (PNRs) and the slowing down of their dynamics. In contrast to the acoustic properties of typical model relaxors such as lead magnesioniobate, the change in the Brillouin shift near its minimum became sharper on heating compared to the change on cooling, pointing to the clear existence of hysteresis in the dynamics of the diffuse phase transition in PZN-4.5%PT. Since the number of PNRs will increase upon cooling, it may be expected that the kinetics of the phase transition would become slower, the lower the transition temperature resulting in the more sluggish, broad feature of the Brillouin shift observed during cooling. This result may indicate that the number and size of polar nanoregions, which are dependent on temperature, play an important role in the development of the mesoscopic ferroelectric order in PZN-4.5%PT.
Show PACS
62.65.+k Acoustical properties of solids
77.80.Dj Domain structure; hysteresis
77.80.B- Phase transitions and Curie point
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
78.35.+c Brillouin and Rayleigh scattering; other light scattering

Optical anisotropy induced by pyramidal defects in Mg-doped AlGaN/GaN superlattices

H. J. Chang, Y. M. Sheu, Y. F. Chen, C. T. Wu, and C. H. Chen

J. Appl. Phys. 100, 066107 (2006); http://dx.doi.org/10.1063/1.2335981 (3 pages)

Online Publication Date: 29 September 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Structural and optical properties of Mg-doped AlGaN/GaN superlattices have been investigated by photoluminescence, scanning electron microscopy, cathodoluminescence (CL), and transmission electron microscopy (TEM). We found that the edge blue-band emission shows a strong optical anisotropy. Through the combination of the CL and TEM images, we clearly establish that the underlying microstructure responsible for the blue luminescence in Mg-doped AlGaN/GaN arises from the pyramidal defects. The observed optical anisotropy is due to the well aligned pyramidal structure. Our result provides one of the model systems to demonstrate the correlation between optical transition and structural defect in a solid.
Show PACS
78.55.Cr III-V semiconductors
78.67.Pt Multilayers; superlattices; photonic structures; metamaterials
68.65.Cd Superlattices
78.60.Hk Cathodoluminescence, ionoluminescence
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close