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

14 Mar 2005

Volume 86, Issue 11, Articles (11xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 86, 113104 (2005); http://dx.doi.org/10.1063/1.1883725 (3 pages)

S. Bhattacharyya, C. Sinturel, J. P. Salvetat, and M.-L. Saboungi
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Impact of oxygen ambient on ferroelectric properties of polar-axis-oriented CaBi4Ti4O15 films

Kazumi Kato, Kiyotaka Tanaka, Kazuyuki Suzuki, Tatsuo Kimura, Kaori Nishizawa, and Takeshi Miki

Appl. Phys. Lett. 86, 112901 (2005); http://dx.doi.org/10.1063/1.1883329 (3 pages) | Cited 8 times

Online Publication Date: 7 March 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Polar-axis oriented CaBi4Ti4O15 (CBTi144) films were fabricated on Pt foils using a complex metal alkoxide solution. The oxygen ambient during crystallization of the films impacted the crystal perfection, crystallite size, and the ferroelectric properties. The 500 mm thick film crystallized in oxygen flow had single columnar structure and in-plane grain size of about 200 nm. The Scherrer’s crystallite diameter was calculated as about 110 nm. The ferroelectric properties were improved. The Pr and Ec of the film enhanced as 33.6 μC/cm2 and 357 kV/cm, respectively, at an applied voltage of 50 V. Voltage applied for full polarization switching was lowered by controlling oxygen stoichiometry of the film. Indeed, the polar-axis-oriented CBTi144 films would open up possibilities for devices as Pb-free ferroelectric materials.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.55.-g Dielectric thin films
77.22.Ej Polarization and depolarization
68.55.-a Thin film structure and morphology
77.80.Fm Switching phenomena
77.22.Gm Dielectric loss and relaxation
77.80.Dj Domain structure; hysteresis
77.22.Ch Permittivity (dielectric function)
64.70.K- Solid-solid transitions
81.40.Tv Optical and dielectric properties related to treatment conditions
68.55.Nq Composition and phase identification

Constrained ferroelectricity in the (001)-textured superlattices of PbZrO3/BaZrO3

Tai-Bor Wu and Cheng-Lung Hung

Appl. Phys. Lett. 86, 112902 (2005); http://dx.doi.org/10.1063/1.1873048 (3 pages) | Cited 6 times

Online Publication Date: 7 March 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A constrained ferroelectricity is found in the (001)-textured PbZrO3/BaZrO3 superlattice films having an average composition of (Pb0.75Ba0.25)ZrO3, which is characterized by the linear dependence of remanent polarization (Pr) and coercive field (Ec) on the applied voltage and its stability against temperature change up to 100 °C. A model based on equilibrium of electrostatic energy in dielectric stressing of the superlattice and polarization switching in the ferroelectric sublayer is proposed. The dielectric constant evaluated from a fitting of the measured Pr and Ec relations to the model is consistent to that obtained from impedance measurement. The thermal stability of this “linear” ferroelectricity can be also explained by the temperature-insensitive permittivity of the superlattice films, according to the proposed model.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
68.65.Cd Superlattices
77.80.Fm Switching phenomena
77.22.Ej Polarization and depolarization
77.22.Ch Permittivity (dielectric function)
77.55.-g Dielectric thin films

Order-disorder nature of ferroelectric BaTi2O5

Anwar Hushur, Hirotake Shigematsu, Yukikuni Akishige, and Seiji Kojima

Appl. Phys. Lett. 86, 112903 (2005); http://dx.doi.org/10.1063/1.1880442 (3 pages) | Cited 17 times

Online Publication Date: 7 March 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Ferroelectric single crystals of BaTi2O5 have been studied in detail by Raman and high-resolution micro-Brillouin scattering with a focus on the central component of the relaxation mode over a wide temperature range (20–600 °C). A relaxation mode has been clearly observed in these single crystals. The temperature dependences of the relaxation time and integrated intensity of the relaxation mode are well reproduced by the extended semiclassical tunneling model. The ferroelectric phase transition shows, at least near the vicinity of Tc, an order-disorder nature. Our results indicate that the spontaneous polarization mainly resulted from the dynamic disorder of the Ti ions in the octahedra along the polar b axis of BaTi2O5.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.80.B- Phase transitions and Curie point
64.70.K- Solid-solid transitions
77.22.Ej Polarization and depolarization
77.22.Gm Dielectric loss and relaxation
78.35.+c Brillouin and Rayleigh scattering; other light scattering
78.30.Hv Other nonmetallic inorganics

Oxygen vacancy migration and time-dependent leakage current behavior of Ba0.3Sr0.7TiO3 thin films

R. Meyer, R. Liedtke, and R. Waser

Appl. Phys. Lett. 86, 112904 (2005); http://dx.doi.org/10.1063/1.1874313 (3 pages) | Cited 29 times

Online Publication Date: 7 March 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The leakage current response of high-permittivity columnar-grown (Ba,Sr)TiO3 thin films has been studied at elevated temperatures under dc load. We observe a thermally activated current prior to the onset of the resistance degradation with an activation energy of EA = 1.1 eV. A point defect model is applied to calculate the migration of electronic and ionic defects under the dc field as well as the current response of the system. We find that the peak in current is not caused by a space-charge-limited transient of oxygen vacancies, but related to a modulation of the electronic conductivity upon oxygen vacancy redistribution. Furthermore, we show that after the redistribution of electronic and ionic defects, no further increase in conductivity takes place in the simulation.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
73.20.Hb Impurity and defect levels; energy states of adsorbed species
77.22.Gm Dielectric loss and relaxation
72.20.Fr Low-field transport and mobility; piezoresistance

Study of the ferroelectricity in Bi2Ti2O7 by infrared spectroscopic ellipsometry

Yun Hou, Zhiming Huang, Jianqiang Xue, Yunian Wu, Xuemin Shen, and Junhao Chu

Appl. Phys. Lett. 86, 112905 (2005); http://dx.doi.org/10.1063/1.1875755 (3 pages) | Cited 3 times

Online Publication Date: 8 March 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Using infrared spectroscopic ellipsometry, the dielectric functions of (111) oriented Bi2Ti2O7 thin films with pyrochlore structure prepared on Pt/Ti/SiO2/Si substrate were determined in the temperature range of 20–70 °C. It is demonstrated that there is a phase transition that appears near 40 °C in terms of static effective charge as a function of temperature calculated from the infrared spectroscopic ellipsometric data of Bi2Ti2O7 thin films. It suggests that the static effective charge is related to the structural distortion, which can facilitate the polarization of Bi2Ti2O7. Accordingly, ferroelectricity in Bi2Ti2O7 is proved by analyzing the infrared dielectric function.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.55.-g Dielectric thin films
77.22.Ch Permittivity (dielectric function)
77.22.Ej Polarization and depolarization
77.80.B- Phase transitions and Curie point
78.66.Nk Insulators
78.30.Hv Other nonmetallic inorganics

Correlation between scanning-probe-induced spots and fixed positive charges in thin HfO2 films

Noriyuki Miyata, Hiroyuki Ota, and Masakazu Ichikawa

Appl. Phys. Lett. 86, 112906 (2005); http://dx.doi.org/10.1063/1.1884750 (3 pages) | Cited 7 times

Online Publication Date: 9 March 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Scanning tunneling microscopy observations revealed unstable species that likely act as fixed positive charges in thin HfO2 films. The density of these species can be practically reduced by low-temperature postdeposition annealing ( ∼ 550°C). The results of various annealing conditions suggest that hydrogenous species created by the reaction of moisture with as-deposited HfO2 films causes this type of fixed positive charges in the films.
Show PACS
77.55.-g Dielectric thin films
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
68.55.-a Thin film structure and morphology
73.61.Ng Insulators
81.40.Gh Other heat and thermomechanical treatments
68.35.B- Structure of clean surfaces (and surface reconstruction)
68.37.Ef Scanning tunneling microscopy (including chemistry induced with STM)

Influence of the oxygen concentration of atomic-layer-deposited HfO2 films on the dielectric property and interface trap density

Jaehoo Park, Moonju Cho, Seong Keun Kim, Tae Joo Park, Suk Woo Lee, Sug Hun Hong, and Cheol Seong Hwang

Appl. Phys. Lett. 86, 112907 (2005); http://dx.doi.org/10.1063/1.1885167 (3 pages) | Cited 28 times

Online Publication Date: 9 March 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The influence of the ozone concentration (160–370 g/m3) during atomic layer deposition of HfO2-gate dielectrics on the dielectric performance of the films grown on Si was studied. Although ozone was effective in reducing the impurity concentration in the film compared to H2O, the higher concentration slightly deteriorated the dielectric performance. More importantly, the degradation in the interface trap property with increasing post-annealing temperature became more serious as the ozone concentration increased. Investigation of the interface states using x-ray photoelectron spectroscopy revealed that the excessive oxygen incorporated during the film growth made the interfacial sub-oxide species (SiO, Si2O3, and silicate) and SiO2 coordinate more with oxygen. This increased the interface trap density and degraded the interface properties.
Show PACS
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
77.55.-g Dielectric thin films
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
61.72.S- Impurities in crystals
79.60.Bm Clean metal, semiconductor, and insulator surfaces
73.20.At Surface states, band structure, electron density of states
77.22.Ch Permittivity (dielectric function)
81.40.Gh Other heat and thermomechanical treatments
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy

Effects of ferroelectric fatigue on the piezoelectric properties (d33) of tetragonal lead zirconate titanate thin films

P. Gerber, C. Kügeler, U. Ellerkmann, P. Schorn, U. Böttger, and R. Waser

Appl. Phys. Lett. 86, 112908 (2005); http://dx.doi.org/10.1063/1.1886259 (2 pages) | Cited 8 times

Online Publication Date: 9 March 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The fatigue of the electromechanical properties of tetragonal PbZrx, Ti1−xO3 thin films is investigated. The decrease of electromechanical small-signal response is compared to the fatigue of the electric properties and examined in detail. Property fatigue is attributed mainly to switching-failure of the unit cells.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.55.-g Dielectric thin films
77.80.Dj Domain structure; hysteresis
77.65.Bn Piezoelectric and electrostrictive constants
77.80.Fm Switching phenomena
77.22.Ej Polarization and depolarization
77.22.Ch Permittivity (dielectric function)

Retention characteristics in Bi3.25La0.75Ti3O12 thin films prepared by the polymeric precursor method

A. Z. Simões, M. A. Ramirez, N. A. Perruci, C. S. Riccardi, E. Longo, and J. A. Varela

Appl. Phys. Lett. 86, 112909 (2005); http://dx.doi.org/10.1063/1.1886893 (3 pages) | Cited 13 times

Online Publication Date: 9 March 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Ferroelectric Bi3.25La0.75Ti3O12 (BLT) thin films were deposited on Pt/Ti/SiO2/Si substrates by the polymeric precursor method. The films present c-axis preferred orientation after annealing at 700 °C for 2 h in conventional furnace. All the capacitors showed good polarization fatigue characteristics at least up to 1×1010 bipolar pulse cycles and excellent retention properties up to 1×104 s. We found that the polarization loss is insignificant with five write∕read voltages at a waiting time of 10 000 S. Independently of the applied electric field the retained switchable polarization approached a nearly steady-state value after a retention time of 10 s.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.55.-g Dielectric thin films
85.50.-n Dielectric, ferroelectric, and piezoelectric devices
84.32.Tt Capacitors
77.80.Dj Domain structure; hysteresis
77.22.Ej Polarization and depolarization
77.80.Fm Switching phenomena
81.15.Lm Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)
68.55.-a Thin film structure and morphology
81.40.Gh Other heat and thermomechanical treatments
81.40.Ef Cold working, work hardening; annealing, post-deformation annealing, quenching, tempering recovery, and crystallization
68.55.A- Nucleation and growth

Al2O3-incorporation effect on the band structure of Ba0.5Sr0.5TiO3 thin films

Y. B. Zheng, S. J. Wang, A. C. H. Huan, C. Y. Tan, L. Yan, and C. K. Ong

Appl. Phys. Lett. 86, 112910 (2005); http://dx.doi.org/10.1063/1.1883712 (3 pages) | Cited 10 times

Online Publication Date: 9 March 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The Al2O3-incoporation effect on the crystal structure and band structure of Ba0.5Sr0.5TiO3 thin films on (100) LaAlO3 substrate has been investigated by x-ray diffraction, x-ray photoelectron spectroscopy, and UV-VIS spectrophotometer. The resultant band gaps (Eg) increase with the increase of Al concentration. The shift of the valence-band edge and the core-level spectra with the incorporation of Al indicates that the Al could reduce the oxygen vacancy concentration.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.55.-g Dielectric thin films
73.20.At Surface states, band structure, electron density of states
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
78.66.Nk Insulators
68.55.-a Thin film structure and morphology
61.72.S- Impurities in crystals
79.60.Dp Adsorbed layers and thin films
79.60.Bm Clean metal, semiconductor, and insulator surfaces
78.40.Ha Other nonmetallic inorganics
61.72.J- Point defects and defect clusters
61.72.Yx Interaction between different crystal defects; gettering effect
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close