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

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue

25 Jun 2007

Volume 90, Issue 26, Articles (26xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 90, 262501 (2007); http://dx.doi.org/10.1063/1.2752015 (3 pages)

Ian Appelbaum and Douwe J. Monsma
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Band offsets and charge storage characteristics of atomic layer deposited high-k HfO2/TiO2 multilayers

S. Maikap, T.-Y. Wang, P.-J. Tzeng, C.-H. Lin, T. C. Tien, L. S. Lee, J.-R. Yang, and M.-J. Tsai

Appl. Phys. Lett. 90, 262901 (2007); http://dx.doi.org/10.1063/1.2751579 (3 pages) | Cited 21 times

Online Publication Date: 25 June 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The band offsets and charge storage characteristics of atomic layer deposited high-k HfO2/TiO2 multilayers with ten periods in p-Si/SiO2/(HfO2/TiO2)/Al2O3 structure have been investigated. The thickness of high-k HfO2 or TiO2 film is ∼ 0.5 nm for each layer, before and after annealing treatment of 900 °C for 1 min in N2 ambient. High-resolution transmission electron microscopy, x-ray photoelectron spectroscopy, and ultraviolet photoelectron spectroscopy measurements on high-k HfO2/TiO2 multilayers confirm the layer-by-layer structure after annealing treatment, suggesting the HfO2/TiO2 multilayer quantum wells. The valence band offsets of HfO2 and TiO2 films are found to be ∼ 3.1 and ∼ 1.5 eV, respectively. The conduction band offsets are found to be ∼ 1.7 eV for HfO2 films and ∼ 0.9 eV for TiO2 films. The high-k HfO2/TiO2 multilayers in p-Si/SiO2/(HfO2/TiO2)/Al2O3/aluminum memory capacitor show a large capacitance-voltage hysteresis memory window of ∼ 5 V at gate voltage of ±5 V, due to the charge storage in multilayer quantum wells. The hysteresis memory window of ∼ 1.3 V at small gate voltage of ±1 V is also observed. The high-k HfO2/TiO2 multilayer memory structure can be used in future nanoscale flash memory device applications.
Show PACS
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
68.65.Ac Multilayers
73.21.Ac Multilayers
61.72.Cc Kinetics of defect formation and annealing
79.60.Jv Interfaces; heterostructures; nanostructures
84.32.Tt Capacitors

Enhancement of field-induced strain by La substitution in epitaxial Pb(Zr,Ti)O3 films grown by metal organic chemical vapor deposition

Ken Nishida, Yoshihisa Honda, Shintaro Yokoyama, Hiroshi Funakubo, Takashi Yamamoto, Keisuke Saito, and Takashi Katoda

Appl. Phys. Lett. 90, 262902 (2007); http://dx.doi.org/10.1063/1.2751580 (3 pages) | Cited 2 times

Online Publication Date: 25 June 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
High-quality epitaxial La-substituted Pb(Zr0.65Ti0.35)O3 films were grown on (100)cSrRuO3‖(100)cSrTiO3 substrates at 600 °C using metal organic chemical vapor deposition. Single-phase perovskite was obtained for La/(Pb+La) ratios ranging from 0 to 33%; La ions were selectively substituted at the Pb sites when the La/(Pb+La) ratio was 6% or less and were substituted at both A and B sites when it was greater than 6%. Both the remanent polarization and coercive field monotonically decreased with the La/(Pb+La) ratio, and the maximum field-induced strain was around 6%. This means that La substitution enhances the field-induced strain.
Show PACS
68.60.Bs Mechanical and acoustical properties
77.22.Ej Polarization and depolarization
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.55.-g Dielectric thin films
68.55.A- Nucleation and growth
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

Phase transitional behavior in K0.5Na0.5NbO3–LiTaO3 ceramics

Yejing Dai, Xiaowen Zhang, and Guoyuan Zhou

Appl. Phys. Lett. 90, 262903 (2007); http://dx.doi.org/10.1063/1.2751607 (3 pages) | Cited 83 times

Online Publication Date: 25 June 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In addition to x-ray diffraction, Raman spectrum measurements provide direct evidence of the tetragonal and orthorhombic phases coexistence in lead-free ceramics (1−x)K0.5Na0.5NbO3 (KNN)–xLiTaO3 when x equals 5 mol %. This is caused by the phase transition temperature between tetragonal and orthorhombic decreasing to around room temperature due to the Li and Ta doping in KNN, and not by constituting a region of morphotropic phase boundary as presented by most published papers. The results indicate that although this kind of ceramic displays good properties, it needs further study to verify if it is suitable to be used in a varying temperature environment.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
64.70.K- Solid-solid transitions
78.30.Hv Other nonmetallic inorganics

Dielectric relaxations in Ca(Fe1/2Nb1/2)O3 complex perovskite ceramics

Y. Y. Liu, X. M. Chen, X. Q. Liu, and L. Li

Appl. Phys. Lett. 90, 262904 (2007); http://dx.doi.org/10.1063/1.2752729 (3 pages) | Cited 16 times

Online Publication Date: 25 June 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Dielectric characteristics of Ca(Fe1/2Nb1/2)O3 ceramics were investigated in wide temperature and frequency ranges. A very high dielectric constant peak with strong frequency dispersion following the Arrhenius law was observed in the temperature range of 473–673 K, and this high temperature dielectric relaxation reflected the defect ordering induced relaxor ferroelectricity. A dielectric constant step associated with a low temperature dielectric relaxation was observed in the temperature range of 200–500 K, but the dielectric constant step was very low ( ∼ 50) and could only be detected in the O2-annealed samples due to the overshadowing amplitude of the high temperature dielectric relaxation. The low temperature dielectric relaxation, following the Arrhenius law, indicated the electronic ferroelectricity due to the ordering among heterovalent iron ions.
Show PACS
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)
77.80.-e Ferroelectricity and antiferroelectricity
81.40.Gh Other heat and thermomechanical treatments

Direct observation of 90° domain switching in lead zirconate titanate thick films using x-ray diffraction

Satoko Osone, Yoshiro Shimojo, Kyle Brinkman, Takashi Iijima, and Keisuke Saito

Appl. Phys. Lett. 90, 262905 (2007); http://dx.doi.org/10.1063/1.2752104 (3 pages) | Cited 4 times

Online Publication Date: 26 June 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Using an x-ray diffraction with reciprocal space mapping, 90° domain switching in tetragonal lead zirconate titanate (PZT) thick films under an applied field was studied. An increase in the c-axis lattice constant and a decrease in the a-axis lattice constant due to the piezoelectric effect and switching from a domain to c domain (90° domain switching) were observed under an applied field. The contribution from 90° domain switching to the total strain was estimated to be 60%–100%, which is almost the same as that for bulk PZT. High value is consistent with the intrinsic nonlinearity in a tetragonal film.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.55.-g Dielectric thin films
77.80.Fm Switching phenomena
77.80.Dj Domain structure; hysteresis
77.65.-j Piezoelectricity and electromechanical effects

Epitaxial growth and dielectric properties of Pb0.4Sr0.6TiO3 thin films on (00l)-oriented metallic Li0.3Ni0.7O2 coated MgO substrates

X. T. Li, P. Y. Du, C. L. Mak, and K. H. Wong

Appl. Phys. Lett. 90, 262906 (2007); http://dx.doi.org/10.1063/1.2752532 (3 pages) | Cited 11 times

Online Publication Date: 26 June 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Highly (00l)-oriented Li0.3Ni0.7O2 thin films have been fabricated on (001) MgO substrates by pulsed laser deposition. The Pb0.4Sr0.6TiO3 (PST40) thin film deposited subsequently also shows a significant (00l)-oriented texture. Both the PST40 and Li0.3Ni0.7O2 have good epitaxial behavior. The epitaxial growth of the PST40 thin film is more perfect with the Li0.3Ni0.7O2 buffer layer due to the less distortion in the film. The dielectric tunability of the PST40 thin film with Li0.3Ni0.7O2 buffer layer therefore reaches 70%, which is 75% higher than that without Li0.3Ni0.7O2 buffer layer, and the dielectric loss of the PST40 thin film is 0.06.
Show PACS
77.55.-g Dielectric thin films
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.22.Gm Dielectric loss and relaxation
68.55.A- Nucleation and growth
68.55.-a Thin film structure and morphology
81.15.Fg Pulsed laser ablation deposition

Probing the ferroelectric phase transition through Raman spectroscopy in Pb(Fe2/3W1/3)1/2Ti1/2O3 thin films

Ashok Kumar, N. M. Murari, R. S. Katiyar, and James F. Scott

Appl. Phys. Lett. 90, 262907 (2007); http://dx.doi.org/10.1063/1.2752535 (3 pages) | Cited 16 times

Online Publication Date: 27 June 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The present work investigates the evolution of micro-Raman spectra of (1−x)Pb(Fe2/3W1/3)O3−xPbTiO3 (PFWT) (x = 0.50) thin films in the temperature range from 80 to 600 K. Raman and dielectric data indicate that the crystal structure changes from tetragonal to cubic, i.e., a ferroelectric phase transition at 575 K. The dielectric properties of PFWT thin films were studied in the temperature range of 80–600 K over a wide range of frequencies. The slope of the reciprocal of the dielectric constant is 2:1, matched well with the simplest Landau free energy model, and it indicates a continuous second order displacive ferroelectric phase transition.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.80.B- Phase transitions and Curie point
77.22.Ch Permittivity (dielectric function)
77.55.-g Dielectric thin films
78.66.Nk Insulators
78.30.Hv Other nonmetallic inorganics

Formation of magnetite in bismuth ferrrite under voltage stressing

X. J. Lou, C. X. Yang, T. A. Tang, Y. Y. Lin, M. Zhang, and J. F. Scott

Appl. Phys. Lett. 90, 262908 (2007); http://dx.doi.org/10.1063/1.2752724 (3 pages) | Cited 17 times

Online Publication Date: 27 June 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Micro-Raman studies show that under ∼ 700 kV/cm of dc voltage stressing for a few seconds, magnetite Fe3O4 forms in thin-film bismuth ferrite BiFeO3, probably due to phase separation. No evidence is found spectroscopically of hemite α-Fe2O3, maghemite γ-Fe2O3, or Bi2O3. This may relate to the controversy regarding the magnitude of magnetization in BiFeO3.
Show PACS
77.55.-g Dielectric thin films
64.75.-g Phase equilibria
78.30.Hv Other nonmetallic inorganics
75.70.Ak Magnetic properties of monolayers and thin films
75.80.+q Magnetomechanical effects, magnetostriction
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.

Study of ferroelectric and reproducible bistable switching properties in CdMnS thin films for nonvolatile memory applications

J. C. Lee, N. G. Subramaniam, J. W. Lee, and T. W. Kang

Appl. Phys. Lett. 90, 262909 (2007); http://dx.doi.org/10.1063/1.2753105 (3 pages) | Cited 6 times

Online Publication Date: 28 June 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
CdMnS thin films grown on indium tin oxide substrate exhibit a ferroelectric property. The remnant polarization of CdMnS films was around 0.025 μC/cm2 for 10% of manganese with a sustained polarization endurance for several cycles. Persisting and highly reproducible bistable switching of about five orders in magnitude between low and high impedance states was observed in current voltage measurements. Nondestructive readout measurement with a short pulse width of 20 μs resulted in a resistance difference of two orders between two read levels with a good retention time. Possible use of CdMnS for nonvolatile memory applications is explored.
Show PACS
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
77.80.Fm Switching phenomena
77.55.-g Dielectric thin films
73.61.Le Other inorganic semiconductors
77.22.Ej Polarization and depolarization
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close