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

9 Oct 2000

Volume 77, Issue 15, pp. 2271-2423

Return to All Sections
back to top
RSS Feeds

Ultraviolet lithography of self-assembled monolayers for submicron patterned deposition

Susanne Friebel, Joanna Aizenberg, Silvia Abad, and Pierre Wiltzius

Appl. Phys. Lett. 77, 2406 (2000); http://dx.doi.org/10.1063/1.1316066 (3 pages) | Cited 20 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on a lithographic technique that uses self-assembled monolayers (SAMs) as a resist to fabricate patterned, chemically functionalized surfaces. Large area line, square, and triangular patterns with a periodicity of 532 nm were generated exposing SAMs of hydrophobic or hydrophilic alkanethiolates to an ultraviolet laser interference pattern at 193 nm for only a few minutes (corresponding to ∼16 J/cm2) followed by the immersion into an alternating thiol. Patterned films of CaCO3, Zn(OH)2, and polymers were directly deposited on these templates. Using substrates patterned with oppositely charged SAMs, large periodic arrays of charged colloids were fabricated. © 2000 American Institute of Physics.
Show PACS
85.40.Hp Lithography, masks and pattern transfer
81.65.Cf Surface cleaning, etching, patterning
68.18.-g Langmuir-Blodgett films on liquids

Nonadiabatic heat-capacity measurements using a superconducting quantum interference device magnetometer

A. I. Kharkovski, Ch. Binek, and W. Kleemann

Appl. Phys. Lett. 77, 2409 (2000); http://dx.doi.org/10.1063/1.1316769 (3 pages) | Cited 1 time

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Nonadiabatic measurements of the heat capacity involving sample-inherent thermometry are proposed. The method is realized with superconducting quantum interference device magnetometry and applied to FeBr2 single crystals by using the magnetization for both thermometry and relaxation calorimetry. When heating with a step pulse of laser light, the magnetization relaxes on a characteristic time scale τ = RC, where C is the heat capacity and R is the heat resistance between the sample and the bath. R is independently determined from the temperature dependence of the magnetic moment measured with and without stationary light irradiation. © 2000 American Institute of Physics.
Show PACS
75.30.Sg Magnetocaloric effect, magnetic cooling
65.40.-b Thermal properties of crystalline solids
65.60.+a Thermal properties of amorphous solids and glasses: heat capacity, thermal expansion, etc.
65.80.-g Thermal properties of small particles, nanocrystals, nanotubes, and other related systems
07.55.Jg Magnetometers for susceptibility, magnetic moment, and magnetization measurements
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
75.30.Cr Saturation moments and magnetic susceptibilities
75.90.+w Other topics in magnetic properties and materials (restricted to new topics in section 75)

Modeling of nitrogen depth profiles in iron after nitriding with a homogenized laser beam

E. Carpene, F. Landry, and P. Schaaf

Appl. Phys. Lett. 77, 2412 (2000); http://dx.doi.org/10.1063/1.1316779 (3 pages) | Cited 8 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this letter we propose a phenomenological model to explain the nitrogen depth profile in iron after laser nitriding. The model is based on the one-dimensional diffusion equation and two sets of functions are use to fit the experimental profiles: complementary error function (erfc) and Gaussian. The different nature of these profiles reflects the presence of two stages in the process: the nitrogen is supplied in the sample as an erfc, while the diffusion to larger depths takes place as Gaussians. © 2000 American Institute of Physics.
Show PACS
81.65.Lp Surface hardening: nitridation, carburization, carbonitridation
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
61.82.Bg Metals and alloys
66.30.J- Diffusion of impurities
61.72.S- Impurities in crystals

Semiconductor sieves as nonlinear optical materials

I. M. Tiginyanu, I. V. Kravetsky, J. Monecke, W. Cordts, G. Marowsky, and H. L. Hartnagel

Appl. Phys. Lett. 77, 2415 (2000); http://dx.doi.org/10.1063/1.1316770 (3 pages) | Cited 34 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Electrochemical etching techniques were used to fabricate semiconductor sieves of gallium phosphide, i.e., two-dimensionally nanostructured membranes exhibiting an enhanced optical second harmonic generation (SHG) in comparison with the bulk material. The SHG rotational and fundamental polarization dependencies studied under sample excitation by a 1064-nm Nd-YAG laser beam indicate optical homogeneity and uniaxial symmetry of the membranes. The artificial anisotropy and the enhanced nonlinear optical response induced by nanotexturization make semiconductor sieves very promising for use in all-optical devices. © 2000 American Institute of Physics.
Show PACS
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
78.66.Fd III-V semiconductors
81.05.Ea III-V semiconductors
81.07.-b Nanoscale materials and structures: fabrication and characterization
81.65.Cf Surface cleaning, etching, patterning
81.05.Rm Porous materials; granular materials
82.45.-h Electrochemistry and electrophoresis
82.39.Wj Ion exchange, dialysis, osmosis, electro-osmosis, membrane processes

Advances in the molecular-beam epitaxial growth of artificially layered heteropolytypic structures of SiC

Andreas Fissel, Bernd Schröter, Ute Kaiser, and Wolfgang Richter

Appl. Phys. Lett. 77, 2418 (2000); http://dx.doi.org/10.1063/1.1311955 (3 pages) | Cited 22 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The controlled growth of SiC heteropolytypic structures consisting of hexagonal and cubic polytypes has been performed by solid-source molecular-beam epitaxy. On on-axis substrates, 4H/3C/4H–SiC(0001) and 6H/3C/6H–SiC(0001) structures were obtained by first growing the 3C–SiC layer some nanometer thick at lower substrate temperatures (T = 1550 K) and Si-rich conditions and a subsequent growth of α-SiC on top of the 3C–SiC layer at higher T (1600 K) under more C-rich conditions. On off-axis substrates, multiheterostructures consisting of 4H/3C- or 6H/3C-stacking sequences were also obtained by first nucleating selectively one-dimensional wire-like 3C–SiC on the terraces of well-prepared off-axis α-SiC(0001) substrates at low T(<1500 K). Next, SiC was grown further in a step-flow growth mode at higher T and Si-rich conditions. After the growth, many wire-like regions consisting of 3C–SiC were found also within the hexagonal layer material matrix indicating a simultaneous step-flow growth of both the cubic and the hexagonal SiC material. © 2000 American Institute of Physics.
Show PACS
68.55.-a Thin film structure and morphology
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy

Supercapacitor electrodes from multiwalled carbon nanotubes

E. Frackowiak, K. Metenier, V. Bertagna, and F. Beguin

Appl. Phys. Lett. 77, 2421 (2000); http://dx.doi.org/10.1063/1.1290146 (3 pages) | Cited 157 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Electrochemical characteristics of supercapacitors built from multiwalled carbon nanotubes electrodes have been investigated and correlated with microtexture and elemental composition of the materials. Capacitance has been estimated by cyclovoltammetry at different scan rates from 1 to 10 mV/s, galvanostatic discharge, and impedance spectroscopy in the frequency range from 100 kHz to 1 mHz. The presence of mesopores due to the central canal and/or entanglement is at the origin of an easy accessibility of the ions to the electrode/electrolyte interface for charging the electrical double layer. Pure electrostatic attraction of ions as well as quick pseudofaradaic reactions have been detected upon varying surface functionality. The values of specific capacitance varied from 4 to 135 F/g, depending on the type of nanotubes or/and their posttreatments. Even with moderate specific surface area (below 470 m2/g), due to their accessible mesopores, multiwalled carbon nanotubes represent attractive materials for supercapacitors as compared to the best activated carbons. © 2000 American Institute of Physics.
Show PACS
84.60.Ve Energy storage systems, including capacitor banks
82.45.-h Electrochemistry and electrophoresis
84.32.Tt Capacitors
61.48.-c Structure of fullerenes and related hollow and planar molecular structures
85.65.+h Molecular electronic devices
82.80.Fk Electrochemical methods
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close