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

23 Feb 2009

Volume 94, Issue 8, Articles (08xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 94, 082501 (2009); http://dx.doi.org/10.1063/1.3085971 (3 pages)

Chunghee Nam, B. G. Ng, F. J. Castaño, M. D. Mascaro, and C. A. Ross
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Field enhancement effect of nanocrystals in bandgap engineering of tunnel oxide for nonvolatile memory application

Yun-Shan Lo, Ke-Chih Liu, Cheng-Wei Cheng, Jyun-Yi Wu, Cheng-Hao Hou, and Tai-Bor Wu

Appl. Phys. Lett. 94, 082901 (2009); http://dx.doi.org/10.1063/1.3077614 (3 pages) | Cited 2 times

Online Publication Date: 23 February 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Charge storage characteristics of metal-oxide-semiconductor (MOS) structures containing Au nanocrystals on tunnel oxide composed of Al2O3/HfO2/Al2O3 stacks in different thickness piling up sequences were investigated. A significant enhancement of charge injection efficiency for both electrons and holes without sacrificing charge retention performance was found in the sample with a relatively thicker ( ∼ 3 nm) Al2O3 sublayer adjacent to Au nanocrystals and a thinner ( ∼ 1 nm) Al2O3 sublayer in front of the Si substrate. It is attributed to the local enhancement of electric field induced by the embedded Au nanocrystals, which greatly modifies the effective barrier of tunnel oxide.
Show PACS
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
84.30.Sk Pulse and digital circuits
61.46.Df Structure of nanocrystals and nanoparticles ("colloidal" quantum dots but not gate-isolated embedded quantum dots)
73.63.Bd Nanocrystalline materials
68.47.Fg Semiconductor surfaces

Aging effect in paraelectric state of ferroelectrics: Implication for a microscopic explanation of ferroelectric deaging

Dezhen Xue, Jinghui Gao, Lixue Zhang, Huixin Bao, Wenfeng Liu, Chao Zhou, and Xiaobing Ren

Appl. Phys. Lett. 94, 082902 (2009); http://dx.doi.org/10.1063/1.3086876 (3 pages) | Cited 5 times

Online Publication Date: 23 February 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Most ferroelectric materials exhibit aging effect (a time-dependent change in physical properties) in their ferroelectric state; however, aging is not reported to exist in the paraelectric state. In this letter we report the existence of a “paraelectric aging effect” in Mn-doped (Ba0.80Sr0.20)TiO3 ceramics. We found that when the paraelectric state is formed from an aged ferroelectric state through a reverse ferroelectric transition, the paraelectric state shows a gradual increase in the dielectric permittivity and decrease in dielectric loss with time. Such paraelectric aging effect exists only in acceptor-doped samples, not in undoped samples. The kinetics of the paraelectric aging follows a simple relaxation function with activation energy of 0.43 eV. Our results suggest that the paraelectric aging stems from the migration of oxygen vacancies, being the same as the case of ferroelectric aging. We show that such a migration is driven by a symmetry-conforming short-range ordering tendency of point defects. Such a microscopic mechanism also provides a microscopic explanation for the well-observed “ferroelectric deaging effect.”
Show PACS
77.80.B- Phase transitions and Curie point
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.22.Gm Dielectric loss and relaxation
77.22.Ch Permittivity (dielectric function)
81.40.Cd Solid solution hardening, precipitation hardening, and dispersion hardening; aging
61.72.jd Vacancies
61.72.up Other materials

Effects of thermal annealing on charge density and N chemical states in HfSiON films

T. Tanimura, H. Kamada, S. Toyoda, H. Kumigashira, M. Oshima, G. L. Liu, Z. Liu, and K. Ikeda

Appl. Phys. Lett. 94, 082903 (2009); http://dx.doi.org/10.1063/1.3088856 (3 pages) | Cited 3 times

Online Publication Date: 24 February 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have investigated the charge density and N chemical states in HfSiON films annealed at various oxygen gas pressures by time-dependent photoemission spectroscopy. The Si 2p core-level spectra and the sample current reveal that annealing these films at low oxygen partial pressures affects the number of inherent fixed charges and annealing at high oxygen partial pressures results in a decrease in the number of trapped charges. The N 1s spectra of the annealed HfSiON samples indicate a decrease in Hf–N bonds due to the substitution of N by O along with a decrease in the number of trapped charges.
Show PACS
77.55.-g Dielectric thin films
61.72.Cc Kinetics of defect formation and annealing
79.60.Bm Clean metal, semiconductor, and insulator surfaces

Magnetic control of polarization and ferroelastic strain switching in Terfenol-D/Bi12GeO20 laminate

Pan Yang, Song Peng, Xiaofei Wang, Xiaomei Lu, Feng Yan, and Jinsong Zhu

Appl. Phys. Lett. 94, 082904 (2009); http://dx.doi.org/10.1063/1.3089571 (3 pages) | Cited 5 times

Online Publication Date: 24 February 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A profound interplay between ferroelastic strain, polarization, and external magnetic field was observed in both bilayer and trilayer laminate Tb0.27–0.30Dy0.73–0.70Fe1.90–1.95 (Terfenol-D)/Bi12GeO20. The bilayer shows a much higher shear strain induced magnetoelectric effect than the trilayer. A series of experimental results related to the ferroelasticity in Bi12GeO20 such as a butterfly loop of the surface strain of Bi12GeO20 to magnetic field and a reproducible magnetic-field-induced strain switching were observed for the bilayer laminate.
Show PACS
77.22.Ej Polarization and depolarization
77.80.Fm Switching phenomena
81.40.Jj Elasticity and anelasticity, stress-strain relations
62.20.D- Elasticity
77.55.-g Dielectric thin films
75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
75.80.+q Magnetomechanical effects, magnetostriction

Switchable rectifier built with Pt/TiOx/Pt trilayer

Hisashi Shima, Ni Zhong, and Hiro Akinaga

Appl. Phys. Lett. 94, 082905 (2009); http://dx.doi.org/10.1063/1.3068754 (3 pages) | Cited 27 times

Online Publication Date: 26 February 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The switchable rectifier built with Pt/TiOx/Pt was proposed and the reproducible rectification switching was demonstrated. The rectification switching is considered to be originated from the electrical control of the oxygen vacancy concentration at the interfaces between Pt and TiOx and resultant variations in the Schottky barrier height. The electrode area dependence of the current conduction after the rectification switching revealed that this switching occurs at the almost entire interface region. The reproducible switching in the Pt/TiOx/Pt rectifier is demonstrated by changing the polarity of the pulse voltage, evidencing the excellent functionality of the engineered metal/oxide interface.
Show PACS
73.40.Ei Rectification
61.72.jd Vacancies
73.40.Rw Metal-insulator-metal structures
73.30.+y Surface double layers, Schottky barriers, and work functions

Temperature-stable and high Q-factor TiO2 Bragg reflector resonator

Jonathan Breeze, Jerzy Krupka, Anthony Centeno, and Neil McN Alford

Appl. Phys. Lett. 94, 082906 (2009); http://dx.doi.org/10.1063/1.3086877 (3 pages) | Cited 2 times

Online Publication Date: 27 February 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The highest Q-factor resonators employ whispering gallery modes in single-crystal sapphire but have poor temperature stability. Rutile was the first dielectric material used to construct a microwave dielectric resonator. However, its very high temperature coefficient of permittivity made it unsuitable for practical applications. This paper reports a high Q-factor (50 000) and temperature-stable spherical Bragg reflector resonator based on polycrystalline rutile operating at 29.9 GHz. Temperature stability is achieved by adjusting the electric filling factor of a spherical shell so that in combination with its highly negative temperature coefficient of permittivity, the effect of thermal expansion is exactly cancelled out.
Show PACS
42.79.-e Optical elements, devices, and systems
85.50.-n Dielectric, ferroelectric, and piezoelectric devices
77.22.Ch Permittivity (dielectric function)
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close