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

Flickr Twitter iResearch App Facebook

SECTION LISTING

BROWSE VOLUMES

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

14 Jun 2004

Volume 84, Issue 24, pp. 4839-5046

Issue Cover Spotlight Figure

Appl. Phys. Lett. 84, 4409 (2004); http://dx.doi.org/10.1063/1.1757648 (3 pages)

Azita Soleymani, Piroz Zamankhan, and William Polashenski
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Multiple relaxation mechanisms in SrTiO3/SrRuO3 heterostructures

Z.-G. Ban, S. P. Alpay, Feizhou He, B. O. Wells, and X. X. Xi

Appl. Phys. Lett. 84, 4848 (2004); http://dx.doi.org/10.1063/1.1760228 (3 pages) | Cited 11 times

Online Publication Date: 25 May 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have studied stress relaxation mechanisms in epitaxial (001) SrTiO3 films grown on (001) LaAlO3 substrates with SrRuO3 buffer layers. A theoretical analysis has been undertaken to understand the variation of the lattice parameters of SrTiO3 epitaxial films, taking into account stress relaxation due to the formation of an orthorhombic polydomain structure in the SrRuO3 buffer layer as well as the formation of misfit dislocations at the LaAlO3/SrRuO3 and the SrTiO3/SrRuO3 interfaces. There exists a critical SrRuO3 buffer layer thickness, above which the SrRuO3 buffer layer can “screen” the effect of the LaAlO3 substrate. It is shown that the internal stress level in films can be controlled using buffer layers that exhibit a structural phase transformation. © 2004 American Institute of Physics.
Show PACS
68.35.Ct Interface structure and roughness
64.70.K- Solid-solid transitions
68.60.Bs Mechanical and acoustical properties
62.40.+i Anelasticity, internal friction, stress relaxation, and mechanical resonances
61.72.Ff Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.)
81.30.Hd Constant-composition solid-solid phase transformations: polymorphic, massive, and order-disorder
68.55.-a Thin film structure and morphology

Determination of dielectric constant of a thin and low-dielectric film in the millimeter wave region

Etsuo Kawate and Kenichi Ishii

Appl. Phys. Lett. 84, 4878 (2004); http://dx.doi.org/10.1063/1.1762975 (3 pages) | Cited 1 time

Online Publication Date: 25 May 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This letter presents a method for measuring free-space transmittance to study the dielectric property of a thin and low-dielectric film in the millimeter wave region. We found that multireflection keeps the height of the repeated peaks of the transmittance almost constant and that their widths quickly narrow with increase in the incident angle. We further show how the dielectric constant is set for a 20-μm-thick silicon dioxide film on a 700-μm-thick silicon substrate near the electromagnetic waves of frequency 65 GHz. © 2004 American Institute of Physics.
Show PACS
77.22.Ch Permittivity (dielectric function)
77.55.-g Dielectric thin films
84.37.+q Measurements in electric variables (including voltage, current, resistance, capacitance, inductance, impedance, and admittance, etc.)

A lead-free high-TC ferroelectric BaTi2O5: A first-principles study

Umesh Waghmare, Marcel H. F. Sluiter, Teiichi Kimura, Takashi Goto, and Yoshiyuki Kawazoe

Appl. Phys. Lett. 84, 4917 (2004); http://dx.doi.org/10.1063/1.1757021 (3 pages) | Cited 18 times

Online Publication Date: 28 May 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Previous experimental indications of ferroelectricity with Curie temperature (TC) of 747 K in BaTi2O5 are confirmed through assessment of its structural stability and estimation of its spontaneous polarization using first-principles density functional theory calculations. The present work establishes that the polarization is observed along b axis only and determines its structural origin with calculations of the Born effective charges. We find its piezoelectric response is comparable to that of PbTiO3, which with its high TC and nonperovskite structure should open up possibilities for new lead-free ferroelectric materials. © 2004 American Institute of Physics.
Show PACS
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
61.66.Fn Inorganic compounds
77.80.B- Phase transitions and Curie point
77.22.Ej Polarization and depolarization

High microwave permittivity of multiwalled carbon nanotube composites

Junhua Wu and Lingbing Kong

Appl. Phys. Lett. 84, 4956 (2004); http://dx.doi.org/10.1063/1.1762693 (3 pages) | Cited 52 times

Online Publication Date: 28 May 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Complex permittivity spectra of the multiwalled carbon nanotube (MWNT)-epoxy composites with mass concentrations up to 25.9% were measured from 10 MHz to 20 GHz. The composites exhibit high real and imaginary relative permittivities over broad bandwidth, showing strong dependence on the MWNT loading. It is observed that distinct resonance takes place at ∼ 1.5 GHz, with the corresponding resonant frequency shifts downward as the MWNT concentration increases. The origin of the dielectric properties is explained in terms of the dielectric relaxation/resonance and electrical conduction behavior of the nanotube composites, substantiated by the agreement between simulation and experimental data. © 2004 American Institute of Physics.
Show PACS
61.46.-w Structure of nanoscale materials
77.22.Ch Permittivity (dielectric function)
77.22.Gm Dielectric loss and relaxation
72.80.Rj Fullerenes and related materials
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects

Effect of operating temperature and film thickness on the pyroelectric response of ferroelectric materials

A. Sharma, Z.-G. Ban, S. P. Alpay, and J. V. Mantese

Appl. Phys. Lett. 84, 4959 (2004); http://dx.doi.org/10.1063/1.1762691 (3 pages) | Cited 13 times

Online Publication Date: 28 May 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The influence of the operating temperature and film thickness on the pyroelectric properties of (001) Ba0.6Sr0.4TiO3 (BST 60/40) epitaxial films on (001) LaAlO3, MgO, and Si substrates is investigated theoretically via a thermodynamic model. The results are presented using contour maps that can be used to identify “design windows” for film thickness and operating temperature for optimum pyroelectric response. For BST 60/40 on LAO and MgO large pyroelectric coefficients ( ∼ 0.7 μC cm−2 K−1) are observed at near room temperature for moderate film thickness (50–200 nm). The pyroresponse of films on Si is suppressed by two orders of magnitude compared to bulk BST 60/40 due to internal stresses. Significant recovery in the pyroelectric coefficient on Si is expected for lower growth temperatures due to the reduction of thermal stresses. © 2004 American Institute of Physics.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.55.-g Dielectric thin films
77.70.+a Pyroelectric and electrocaloric effects
77.80.-e Ferroelectricity and antiferroelectricity

Nitrogen bonding, stability, and transport in AlON films on Si

G. V. Soares, K. P. Bastos, R. P. Pezzi, L. Miotti, C. Driemeier, I. J. R. Baumvol, C. Hinkle, and G. Lucovsky

Appl. Phys. Lett. 84, 4992 (2004); http://dx.doi.org/10.1063/1.1763230 (3 pages) | Cited 16 times

Online Publication Date: 28 May 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The chemical environment of N in nitrided aluminum oxide films on Si(001) was investigated by angle-resolved x-ray photoelectron spectroscopy. Two different bonding configurations were identified, namely N–Al and N–O–Al, suggesting the formation of the AlN and AlO2N compounds. The near-surface region is N-rich and AlN compounds therein are more abundant than AlO2N, whereas in bulk regions the proportions of these two compounds are comparable. Rapid thermal annealing at 1000 °C for 10 s in vacuum or in low-pressure oxygen atmosphere led to the breakage of N–Al bonds in AlN, releasing N and Al. The mobile N is partly lost by desorption from the surface and partly fixed by reacting with the network to form AlO2N. The released Al atoms, which remain immobile, react with oxygen from the film or from the gas phase. Characterization of the films outermost surfaces by low-energy ion scattering revealed that the migration of Si atoms from the substrate across the films, reaching the surface and being oxidized therein, is not entirely inhibited in AlON/Si, although this migration is largely reduced as compared to nonnitrided Al2O3 films. © 2004 American Institute of Physics.
Show PACS
77.55.-g Dielectric thin films
82.80.Pv Electron spectroscopy (X-ray photoelectron (XPS), Auger electron spectroscopy (AES), etc.)
81.40.Gh Other heat and thermomechanical treatments
68.43.Mn Adsorption kinetics
68.55.Nq Composition and phase identification
81.65.Mq Oxidation
68.35.B- Structure of clean surfaces (and surface reconstruction)

Bi modification for low-temperature processing of YMnO3 thin films

Taekjib Choi and Jaichan Lee

Appl. Phys. Lett. 84, 5043 (2004); http://dx.doi.org/10.1063/1.1763642 (3 pages) | Cited 6 times

Online Publication Date: 28 May 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
YMnO3 thin films have been modified by Bi for low-temperature processing. YMnO3 thin-film growth typically requires high temperatures possibly leading to undesirable interface reaction and device failure in further processing. We have proposed Bi modification into YMnO3 (YBM) thin films grown on Si (100) by pulsed-laser deposition for reduced temperature processing. The growth temperature of YBM films was significantly reduced by more than 150 °C from the typical growth temperature of YMnO3 films. Highly c-axis-oriented growth of hexagonal YBM films at low temperatures was effective above 5% Bi content modification. Surface analysis on YBM films suggests that very thin Bi oxide layer forms on the topmost growing surface of YBM films and enhances the surface mobility of adatoms, leading to enhanced crystallization and low-temperature processing. The Bi modification did not deteriorate the electrical properties of YMnO3 such as dielectric constant and leakage current. This Bi modification can be an effective method to reduce processing temperature for other oxide thin films in physical vapor deposition. © 2004 American Institute of Physics.
Show PACS
81.15.Fg Pulsed laser ablation deposition
77.80.-e Ferroelectricity and antiferroelectricity
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
77.55.-g Dielectric thin films
77.22.Ch Permittivity (dielectric function)
73.61.-r Electrical properties of specific thin films
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close