scholarly journals Механизмы поглощения терагерцового и инфракрасного излучения в пленках PZT

2018 ◽  
Vol 60 (6) ◽  
pp. 1214
Author(s):  
Г.А. Командин ◽  
О.Е. Породинков ◽  
И.Е. Спектор ◽  
А.А. Волков ◽  
К.А. Воротилов ◽  
...  
Keyword(s):  
Ir Spectra ◽  
Single Crystal ◽  
Electric Dipole ◽  
Dielectric Response ◽  
Silicon Substrates ◽  
Transmission Spectra ◽  
Absorption Bands ◽  
Reflection And Transmission ◽  
Pzt Films ◽  
The Relationship

AbstractTerahertz and IR spectra of dielectric response of dense and porous Pb(Zr,Ti)O_3 films deposited on single-crystal magnesia and alumina substrates and on silicon substrates with a conducting platinum sublayer are measured in the and analyzed. We consider the key mechanisms of electric dipole absorption that give rise to absorption bands observed in experimentally measured reflection and transmission spectra, and discuss the relationship between the type of substrate and the parameters characterizing the absorption bands in the spectra of the prepared PZT films.

The Effects of Deoxidants on Ge-Se-Te Chalcogenide Glasses

2011 ◽  
Vol 103 ◽  
pp. 458-463
Author(s):  
Xun Si Wang ◽  
Jie Sun ◽  
Qiu Hua Nie ◽  
Shi Xun Dai ◽  
Xiang Hua Zhang ◽  
...  
Keyword(s):  
Chalcogenide Glasses ◽  
Transmission Spectra ◽  
Absorption Bands ◽  
Minimum Concentration ◽  
Impurity Absorption ◽  
Ir Transmission ◽  
Different Content ◽  
The Relationship ◽  
Concentration Of Impurities ◽  
Main Impurity

In order to decrease the impurity absorption bands of Ge-Se-Te chalcogenide glasses in IR region. Three different kinds of deoxidants including Mg(magnesium), Al(aluminium) and Ca(calcium) were chosen. Properties measurements including density, Vis-NIR and infrared (IR) transmission spectra were adopted to analyze the relationship between impurity absorption bands and deoxidants. The concentrations of impurities in glass samples with different content of Mg were calculated by method of optic spectra. The results show that Mg is a better choice as deoxidant for chalcogenide glasses compared to Al and Ca. The values of main impurity concentration decrease from 4417.833 to 0 ppmw for Ge-O and from 55.236 to 0 ppmw for Si-O with increasing content of Mg, respectively. At least 200ppm Mg is needed to minimize the main absorption bands in IR region and G5 glass incorporated with 400ppm Mg has minimum concentration of impurities which means that it possesses the optimal transmission properties.

Ferroelectric Thin Films by sol-gel Processing

1989 ◽  
Vol 152 ◽  
Author(s):  
S. L. Swartz ◽  
P. J. Melling ◽  
C. S. Grant
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Sol Gel ◽  
Fused Silica ◽  
Ferroelectric Materials ◽  
Ferroelectric Thin Films ◽  
Silicon Substrates ◽  
Heat Treated ◽  
Pzt Films ◽  
Gel Processing

ABSTRACTThe sol-gel processing of ferroelectric thin films is being investigated at Battelle. The ferroelectric materials included in this study are PbTiO3, Pb(Zr, Ti)O3 (PZT), and KNbO3. The sol-gel processing and crystallization of these films on fused silica, silicon, alumina, and single crystal SrTiO3 substrates is described.Sol-gel derived PbTiO3 thin films crystallized into the expected tetragonal perovskite structure when heated to 500 C and above. However, the crystallization of sol-gel PZT (20/80) thin films was found to be substratedependent. The heat-treated PZT films were amorphous when deposited on silica and silicon substrates. Crystalline perovskite PZT films were produced on alumina substrates, and epitaxial PZT films were produced on single-crystal SrTiO3. Heat treatment of sol-gel KNbO3 films on silicon and alumina substrates resulted in the crystallization of a variety of non-perovskite phases, but epitaxial growth of KNbO3 was observed on single crystal SrTiO3.

Epitaxial-like growth of solution-processed PbZr0.4Ti0.6O3 thin film on single-crystal Nb-doped SrTiO3 substrate

2017 ◽  
Vol 33 (4) ◽  
Author(s):  
TRINH BUI
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Annealing Temperature ◽  
Bottom Electrode ◽  
Solution Process ◽  
Silicon Substrates ◽  
Homogeneous Surface ◽  
Pzt Thin Films ◽  
Niobium Doped ◽  
Pzt Films

PbZr0.4Ti0.6O3 (PZT) thin films have been conventionally fabricated on traditional silicon substrates with a platinum bottom electrode; however, as a consequence of unit cell mismatch, the films are difficult to form as an epitaxial-like growth. Hence, PZT films deposited on single-crystal niobium doped SrTiO3(111) substrates (Nb:STO) are promising to solve this issue thanks to the similar perovskite structure between PZT and STO. Essentially, Nb:STO material is a conductor, playing a part in both bottom electrode and epitaxial substrate. In this work, 200-nm-thick PZT films were successfully fabricated on Nb:STO substrates by a solution process. One obtained that PZT(111) peak started to appear on the Nb:STO substrate at a low annealing temperature of 450oC. Also, scanning electron microscopy observation shows smooth and homogeneous surface of PZT films on Nb:STO substrate with no grain boundary, which evidences for epitaxial-like growth of PZT thin films. Remnant polarization of 6 µC/cm2 and leakage current of 8×10-8 A were obtained at applied voltage of 5 V.

scholarly journals Optical Properties of Monocrystalline Silicon Nanowires

2021 ◽  
Vol 22 (3) ◽  
pp. 453-459
Author(s):  
P.O. Gentsar ◽  
A.V. Stronski ◽  
L.A. Karachevtseva ◽  
V.F. Onyshchenko
Keyword(s):  
Porous Silicon ◽  
Single Crystal ◽  
Silicon Nanowires ◽  
Single Crystal Silicon ◽  
Single Crystal Substrate ◽  
Transmission Spectra ◽  
Crystal Silicon ◽  
Reflection And Transmission ◽  
Crystal Matrix ◽  
Crystal Substrate

The paper presents the results of a study of the optical reflection and transmission spectra of a silicon single crystal p-Si (100) with silicon nanowires grown on both sides and porous silicon p-Si (100) on a single crystal substrate in the spectral range 0.2 ÷ 1.7 μm. The layers of nanowires had a thickness of 5.5 µm, 20 µm, 50 µm and a porosity of 60 %. The porous silicon layers had a thickness of 5 μm, 50 μm and a porosity of 45 %, 55 % and 65 %. The change in the energy band structure in single-crystal silicon nanowires and in a single-crystal matrix of porous silicon is shown.

Relaxor Single Crystals with Giant k31 Mode

2006 ◽  
Vol 45 ◽  
pp. 2412-2421
Author(s):  
Toshio Ogawa
Keyword(s):  
Single Crystal ◽  
Electromechanical Coupling ◽  
Impedance Measurement ◽  
Hysteresis Loops ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Poling Direction ◽  
Length Direction ◽  
Relaxor Single Crystals ◽  
The Relationship

Giant electromechanical coupling factor of k31 mode over 86% was found for (100) Pb[(Zn1/3Nb2/3)0.91Ti0.09]O3 and (110) Pb[(Mg1/3Nb2/3)0.74Ti0.26]O3 single-crystal plates poled in the [100] and [110] directions, respectively. The P-E hysteresis loops in the single-crystal plates with giant k31 became asymmetric. Furthermore, the frequency response of impedance in these plates with giant k31 consisted of a single vibration in the length direction. A mechanism to realize giant k31 can be explained by the relationship between the crystal plane and poling direction. In addition, the existence of giant piezoelectric d31 constant was proven by the strain measurement as well as by the impedance measurement.

The effect of Al/Si disorder on the bulk moduli of plagioclase feldspars

2010 ◽  
Vol 74 (6) ◽  
pp. 943-950 ◽  
Author(s):  
L. M. Sochalski-Kolbus ◽  
R. J. Angel ◽  
F. Nestola
Keyword(s):  
Bulk Modulus ◽  
Single Crystal ◽  
Equations Of State ◽  
X Ray Diffraction ◽  
Volume Increase ◽  
X Ray ◽  
Density Decrease ◽  
The Relationship

AbstractThe volumes of a disordered An20 (Qod = 0.15), a disordered An78 (Qod = 0.55) and an ordered An78 (Qod = 0.81) were determined up to 9.569(10) GPa, 8.693(5) GPa and 9.765(10) GPa, respectively, using single-crystal X-ray diffraction. The volume variations with pressure for these samples are described with 4th-order Birch Murnaghan equations of state with V0 = 669.88(7) Å3, K0 = 59.7(7) GPa. K′ = 5.7(5), K″ = −0.8(2) GPa−1 for disordered An20, V0 = 1340.48(10) Å3, K0 = 77.6(5) GPa, K0′ = 4.0(3), K″ = -0.59(9) GPa−1 for disordered An78 and V0 = 1339.62(6) A3, K0 = 77.4(6) GPa, K′ = 4.2(4), and K″ = −0.7(1) GPa−1 for ordered An78. Along with data from previous studies (An0 ordered, An0 disordered and An2o ordered), the volumes for the disordered samples were found to be up to ∼0.3% larger than the ordered samples of the same composition. The disordered samples are softer than the ordered samples of the same composition by 4(1)% for An0, 2.5(9)% for An20 and essentially zero for An78. The relationship between volume increase, density decrease, and decreasing bulk modulus with increasing disorder is in accordance with Birch's Law.

scholarly journals The Chemistry and Physics of Nonlinear Optical Materials: A new look at an Old Field

1989 ◽  
Vol 152 ◽  
Author(s):  
Stephan P. Velsko ◽  
David Eimerl
Keyword(s):  
Dielectric Response ◽  
Optical Materials ◽  
Nonlinear Optical ◽  
Theoretical Description ◽  
Nonlinear Optical Materials ◽  
Old Field ◽  
Rigorous Bounds ◽  
Linear And Nonlinear ◽  
The Relationship ◽  
Molecular Orbital Model

Recent efforts to “engineer” new nonlinear optical materials with specific desired characteristics has engendered a need for a theoretical description of optical properties which is readily accessible to chemists, yet correctly treats the essential physics of dielectric response. This paper describes a simple empirical molecular orbital model which gives useful insights into the relationship between chemical composition, crystalline structure, and optical susceptibilities. We compare the probabilities of finding new harmonic generators in various chemical classes. Rigorous bounds on the magnitudes of linear and nonlinear optical coefficients and their anisotropies are also discussed.

Hetero-Epitaxial Growth of 3C-SiC on Silicon Substrates by Plasma Assisted CVD

2006 ◽  
Vol 527-529 ◽  
pp. 299-302
Author(s):  
Hideki Shimizu ◽  
Yosuke Aoyama
Keyword(s):  
Substrate Temperature ◽  
Single Crystal ◽  
Epitaxial Growth ◽  
Deposition Rate ◽  
Crystalline Structure ◽  
Flow Rate ◽  
Silicon Substrates ◽  
High Quality ◽  
Sic Films ◽  
Lower Substrate Temperature

3C-SiC films grown on carbonized Si (100) by plasma-assisted CVD have been investigated with systematic changes in flow rate of monosilane (SiH4) and propane (C3H8) as source gases. The deposition rate of the films increased monotonously and the microstructures of the films changed from 3C-SiC single crystal to 3C-SiC polycrystal with increasing flow rate of SiH4. Increasing C3H8 keeps single crystalline structure but results in contamination of α-W2C, which is a serious problem for the epitaxial growth. To obtain high quality 3C-SiC films, the effects of C3H8 on the microstructures of the films have been investigated by reducing the concentration of C3H8. Good quality 3C-SiC single crystal on Si (100) is grown at low net flow rate of C3H8 and SiH4, while 3C-SiC single crystal on Si (111) is grown at low net flow rate of C3H8 and high net flow rate of SiH4. It is expected that 3C-SiC epitaxial growth on Si (111) will take placed at a higher deposition rate and lower substrate temperature than that on Si (100).

Sign in / Sign up

Export Citation Format

Share Document