jap banner
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

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

15 Jul 2000

Volume 88, Issue 2, pp. 605-1196

Return to All Sections
back to top
RSS Feeds

(Mn, Sb) doped-Pb(Zr, Ti)O3 infrared detector arrays

Y. Q. Xu, N. J. Wu, and A. Ignatiev

J. Appl. Phys. 88, 1004 (2000); http://dx.doi.org/10.1063/1.373769 (4 pages) | Cited 10 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
(Mn, Sb) doped Pb(Zr, Ti)O3 (PMSZT) thin film infrared (IR) detectors were integrated with Si substrates. The epitaxial PMSZT thin films, deposited on c-axis oriented YBa2Cu3O7−y (YBCO) bottom electrodes, show good ferroelectric properties with a remnant polarization Pr of 31 μC/cm2, a spontaneous polarization Ps of 38 μC/cm2, and a coercive field Ec of 21 kV/cm under an electric field of 76 kV/cm. Doping with Mn and Sb into Pb(Zr, Ti)O3 (PZT) not only decreased the Curie temperature TC from 350 °C for PZT to 175 °C for PMSZT, but also enhanced IR responsivity significantly. PMSZT thin films show high figures of merit, Fi of 15.5×10−9 C cm/J, Fv of 1758 cm2/C and Fd of 5×10−5 Pa−1/2 at 25 °C. IR detector arrays, fabricated with PMSZT films deposited on YBCO microbridges with an air gap between them and the substrate for reduced thermal mass, show a higher IR voltage responsivity compared to those without an air gap. © 2000 American Institute of Physics.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors
77.22.Ej Polarization and depolarization
77.80.B- Phase transitions and Curie point
77.55.-g Dielectric thin films

Sol-gel derived Ba(Fe, Ti)O3 ferroelectric materials for infrared sensors

Jayati Ray (Mal) and Peter Hing

J. Appl. Phys. 88, 1008 (2000); http://dx.doi.org/10.1063/1.373770 (7 pages) | Cited 6 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this article we report the development of Fe modified BaTiO3 using sol-gel technique and present results of structural and dielectric studies to establish its suitability for pyroelectric sensor applications. Fine powders of Fe modified BaTiO3 were prepared by sol-gel process using barium acetate, iron isopropoxide, and titanium isopropoxide. X-ray structural analyses of the BaTiO3 with different proportion of Fe ion suggest the formation of single-phase compounds having tetragonal structure at a relatively low temperature around 750 °C for 4 h. The particle size of the powder was found to be in nm range. The sintering temperature of 1250 °C for the above calcined powder was considerably lower than the powders made by the conventional methods. The ferroelectric to paraelectric phase transition of Ba(Fe, Ti)O3 ceramics was studied using the dielectric measurement. The value of dielectric constant for Fe modified BaTiO3 was found to be lower than pure BaTiO3 and the transition temperature shifted towards the lower temperature side with an increase in Fe ion concentration. A combination of low dielectric constant and a low transition temperature makes Fe modified BaTiO3 materials attractive for room temperature pyroelectric sensor applications. © 2000 American Institute of Physics.
Show PACS
81.05.Je Ceramics and refractories (including borides, carbides, hydrides, nitrides, oxides, and silicides)
81.10.Dn Growth from solutions
81.10.Fq Growth from melts; zone melting and refining
81.15.Lm Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.80.B- Phase transitions and Curie point
85.60.Gz Photodetectors (including infrared and CCD detectors)
85.50.-n Dielectric, ferroelectric, and piezoelectric devices
77.22.Ch Permittivity (dielectric function)

Crystal structure and dielectric relaxation studies of the [N(CH3)3H]3Sb2(1−x)Bi2xCl9 mixed crystals

G. Bator, R. Jakubas, J. Zaleski, and J. Mróz

J. Appl. Phys. 88, 1015 (2000); http://dx.doi.org/10.1063/1.373771 (9 pages) | Cited 12 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The influence on ferroelectric properties of a partial substitution of antimony by bismuth in the [N(CH3)3H]3Sb2Cl9 (TMACA) crystals are investigated by dielectric and x-ray diffraction methods. The dielectric relaxation in the [N(CH3)3H]3Sb2(1−x)Bi2xCl9 (TMACAB) mixed crystals (x=0, 0.07, 0.33, 0.38, and 1) is studied in the frequency range between 20 Hz and 1 GHz and temperature range between 170 and 375 K. The ferroelectric properties of mixed crystals are preserved for the Bi concentration less than 0.33. The increase of the Bi concentration distinctly influences the phase transition temperature but only weakly the dynamical properties of those crystals. The dielectric response of the ferroelectric TMACAB crystals is characterized by a presence of two relaxation modes. One of them behaves critically and the other one is only thermally activated. The disappearance of ferroelectric properties is connected with the essential change of crystal structure of mixed compounds. The anionic sublattice of nonferroelectric TMACAB (x>0.33) (Rmathc space group) instead of two-dimensional layers is composed of the isolated Sb2(1−x)Bi2xCl9 bioctahedral units. © 2000 American Institute of Physics.
Show PACS
77.84.Jd Polymers; organic compounds
61.66.Hq Organic compounds
77.22.Gm Dielectric loss and relaxation
77.80.B- Phase transitions and Curie point

Modeling of laser-induced breakdown in dielectrics with subpicosecond pulses

T. Apostolova and Y. Hahn

J. Appl. Phys. 88, 1024 (2000); http://dx.doi.org/10.1063/1.373772 (11 pages) | Cited 26 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Theoretical study of ultrafast laser induced damage by short pulses (τ<1 ps) is carried out on large-band-gap dielectric in an effort to understand the complex physical processes involved. The numerical method of solving a general time-dependent Fokker–Planck type equation for free electron production is discussed in detail. The calculation shows that the collisional avalanche ionization competes with the multiphoton ionization even for pulse length shorter than 25 fs. Sensitivity tests of all the rates in the equation are performed and the most critical ones are identified. From these tests we obtain valuable information in developing new materials that have the desired damage fluence for specific applications. To describe the relaxation of electron plasma, a three body recombination rate is included. Thus, the temporal behavior of the electron density due to a single pulse is treated, as well as the case of exposure to two laser pulses with a time delay between them. The model is only partially successful in reproducing the recent experimental data. Effect of the presence of a linear decay term and optical defects on the damage threshold is considered in the context of the rate equation input. © 2000 American Institute of Physics.
Show PACS
77.22.Jp Dielectric breakdown and space-charge effects
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
02.30.-f Function theory, analysis
72.20.Ht High-field and nonlinear effects

Effects of processing on the characteristics of SrBi2Ta2O9 films prepared by metalorganic decomposition

Aidong Li, Di Wu, Huiqin Ling, Tao Yu, Mu Wang, Xiaobo Yin, Zhiguo Liu, and Naiben Ming

J. Appl. Phys. 88, 1035 (2000); http://dx.doi.org/10.1063/1.373773 (7 pages) | Cited 12 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
SrBi2Ta2O9(SBT) films were prepared by metalorganic decomposition technique. The films were obtained by spin-on pyrolysis of the precursor solutions on various substrates and then annealed at 550–850 °C in dry oxygen, wet oxygen, or Ar. Effects of precursor solution concentration, anneal temperature, anneal atmosphere, substrate and Ar ion sputtering on the microstructure, morphology and electrical properties were investigated by means of x-ray diffraction, scanning electron microscope, atomic force microscope, x-ray photoelectron spectroscopy, and electrical measurements. The results indicated the grain size, and the remnant polarization (Pr) increased with increasing the anneal temperature up to 800 °C and the significant hysteresis loop could be obtained only after anneal above 700 °C. At 850 °C, the pyrochlore phase and other secondary phases were observed along with the SBT phase, leading to the decreasing Pr and dielectric constant. In addition, the development of crystalline phase and electrical properties were affected by anneal atmosphere. When annealed in Ar at 750 °C, the layered SBT structure was destroyed with evident Bi loss. As though the original structure could be restored basically by subsequent adequate O2 anneal, the electrical properties were deteriorated seriously due to the shorted capacitor. Wet oxygen anneal evidently deformed the morphology and the hysteresis loop. This was attributed to the effect of possible produced slight H2 due to the reaction between H2O and residual carbonaceous in films under Pt catalyst. Substrates also played an important role on film crystallinity. The films deposited on Si, SrTiO3, and crystal quartz at 750 °C had a layered perovskite polycrystalline structure while the films on fused quartz exhibited poor crystalline nature even after 800 °C anneal and films on NaCl showed (200)-predominant orientation of SBT phase with some pyrochlore. In addition, Ar ion sputtering might lead to the severe Bi and oxygen deficiency in the surface of the sputtered film. © 2000 American Institute of Physics.
Show PACS
77.55.-g Dielectric thin films
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.22.Ej Polarization and depolarization
77.80.Dj Domain structure; hysteresis
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
79.60.Bm Clean metal, semiconductor, and insulator surfaces
77.22.Ch Permittivity (dielectric function)
61.72.Cc Kinetics of defect formation and annealing
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces

Light-induced charge-transport properties of photorefractive barium–calcium–titanate crystals doped with iron

H. Veenhuis, T. Börger, K. Buse, C. Kuper, H. Hesse, and E. Krätzig

J. Appl. Phys. 88, 1042 (2000); http://dx.doi.org/10.1063/1.373774 (8 pages) | Cited 7 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Nominally pure and iron doped, as-grown, and thermally annealed photorefractive barium–calcium–titanate crystals of the congruently melting composition Ba0.23Ca0.77TiO3 (BCT) are investigated by holographic and conventional electrical techniques. Refractive-index changes, two-beam-coupling gains, photoconductivities, dark conductivities, and bulk-photovoltaic current densities are measured. As-grown and oxidized crystals are hole conductive and at usual illumination conditions (light wavelength 514.5 nm, light intensity between 0.1 and 1 W/cm2) all measured properties are excellently described by an one-center charge-transport model. The effective electrooptic coefficient r333 is only about 30 pm/V and thus much smaller than the value obtained from interferometric measurements. Two-beam-coupling gains as high as 7 cm−1 are achieved. Doping with iron increases considerably the effective trap density, and bulk-photovoltaic fields of the order of some kilovolts per centimeter are observed in iron-doped crystals. Typical response times of iron-doped, as-grown, or oxidized crystals are about 0.5 s at 1 W/cm2. Reduction yields electron-conductive BCT. The dark storage time increases from 6 min in the as-grown state to 3 h upon a slight reduction treatment, but decreases for strongly reduced samples. The investigation reveals that BCT will become a very promising alternative to barium–titanate crystals (BaTiO3) for many applications. © 2000 American Institute of Physics.
Show PACS
72.40.+w Photoconduction and photovoltaic effects
42.70.Gi Light-sensitive materials
42.40.Ht Hologram recording and readout methods
42.70.Ln Holographic recording materials; optical storage media
42.70.Nq Other nonlinear optical materials; photorefractive and semiconductor materials
81.40.Gh Other heat and thermomechanical treatments
81.40.Tv Optical and dielectric properties related to treatment conditions
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
78.20.Jq Electro-optical effects
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close