The Effect of (Ba,Sr) and (Mn,Fe,W) Dopants on the Microwave Properties of BaxSr1−xTiO3 Thin Films

1998 ◽  
Vol 541 ◽  
Author(s):  
Wontae Chang ◽  
James S. Horwitz ◽  
Won-Jeong Kim ◽  
Jeffrey M. Pond ◽  
Steven W. Kirchoefer ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Bias Field ◽  
Film Structure ◽  
Single Crystal Substrate ◽  
Microwave Frequencies ◽  
Anion Vacancies ◽  
Crystal Substrate ◽  
Cation And Anion Vacancies ◽  
Donor Acceptor

AbstractSingle phase BaxSr1−xTiO3 (x=0.5 and 0.6) thin films (∼5000Å thick) have been deposited onto (100) MgO single crystal substrate with (Ba,Sr) compensated and/or (Mn,Fe,W) doped targets using pulsed laser deposition (PLD). The room temperature capacitance (C) and dielectric Q (1/tanδ) have been measured at microwave frequencies of I to 20 GHz as a function of electric field (0-80kV/cm). Microstructural defects associated with cation and anion vacancies have been observed in BaxSr1−xTiO3 films. Compensation of the ablation target with excess Ba and Sr tends to increase the dielectric constant and the dielectric Q. A film deposited with (Ba,Sr) compensated target has been obtained with 25% tuning, where % tuning is defined as {(C(0)-C(E))/C(O))×100, and dielectric Q of ∼ 100 at room temperature (1 — 10 GHz) for DC bias field (E=67 kV/cm). A further increase in the dielectric Q is observed by the addition of donor/acceptor dopants such as Mn, Fe, and W (Q≈100-240). The effects of (Ba, Sr) compensation and (Mn,Fe,W) doping on the film structure and dielectric properties are discussed.

Morphological transformations in solution-cast Styrene-Butadiene-Styrene (SBS) triblock copolymer thin films

1995 ◽  
Vol 53 ◽  
pp. 184-185
Author(s):  
Ginam Kim ◽  
W. Marsillo ◽  
M. Libera
Keyword(s):  
Thin Films ◽  
Triblock Copolymer ◽  
Annealing Treatment ◽  
Minor Component ◽  
Solvent Evaporation ◽  
Single Crystal Substrate ◽  
Transparent Films ◽  
Crystal Substrate ◽  
Solution Cast ◽  
Morphological Transformations

The fact that block copolymers can assume a range of morphologies depending upon such variables as relative block length and molecular weight is now well known. In the case of poly(styrene)[PS]-poly(butadiene)[PB]-poly(styrene) (SBS) triblock copolymer, the morphologies range from spheres (roughly ~20% minor component), to cylinders (roughly 20%~35% minor component), to lamellae (roughly equal component fractions) Most recently, there has been increasing interest in transformations between morphologies by thermal annealing. This paper describes initial results studying the effect of solvent evaporation rate and post-casting annealing treatment on the morphology of SBS thin films.TEM specimens were prepared by solution casting electron transparent films. 50 μl of 0.1 wt% SBS (30% styrene, Mw=14,000, Scientific Polymer Products, Inc.) dissolved in toluene was deposited on a polished NaCl single crystal substrate placed in a small dish. After solvent evaporation the film was cut into small squares, floated from the salt in water, and each square was collected on a Cu grid.

Microstructure and enhanced in-plane ferroelectricity of Ba0.7Sr0.3TiO3 thin films grown on MgAl2O4 (001) single-crystal substrate

2006 ◽  
Vol 89 (23) ◽  
pp. 232906 ◽  
Author(s):  
X. Y. Zhou ◽  
T. Heindl ◽  
G. K. H. Pang ◽  
J. Miao ◽  
R. K. Zheng ◽  
...  
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Single Crystal Substrate ◽  
Crystal Substrate

Electro-Optic Properties of (100)-Oriented (Pb,La(Zr,Ti)O3 Thin Film

2012 ◽  
Vol 185 ◽  
pp. 60-64
Author(s):  
Min Min Zhu ◽  
Ze Hui Du ◽  
Jan Ma
Keyword(s):  
Thin Films ◽  
Near Infrared ◽  
Infrared Light ◽  
Single Crystal Substrate ◽  
Light Wavelength ◽  
Prism Coupler ◽  
Electro Optic ◽  
Crystal Substrate ◽  
Tm Model ◽  
Plzt Thin Films

(100)-oriented PLZT ((Pb1-x, Lax) (Zry,Ti1-y)1-x/4O3, x/y=9/65) films of up to ~ 1.23 μm have been developed on LaAlO3single crystal substrate by magnetron sputtering. The as-grown PLZT thin films exhibit high optical transparency in visible and near-infrared light wavelength and high quadratic (Kerr) EO coefficients. Prism coupler measurements reveal that the PLZT thin films possess large refractive index, as high as 2.524 in TE model and 2.481 in TM model. The transparency of >70% in the range of λ= 500-1200 nm, the optic band gap of 3.42 eV and the quadratic electro-optic (EO) coefficient of 3.38 x 10-17(m/V)2have been measured in the films. Due to the large EO coefficient and the micrometric thickness, the as-developed PLZT films have great potential in developing longitudinal-or transverse-type EO devices in electric and optic field

Superconducting Yttrium Barium Copper Oxide Thin Films Growing on the Strained Substrates

2008 ◽  
Vol 3 (4) ◽  
pp. 25-32
Author(s):  
Aleksandr V. Zakharov ◽  
Aleksandr B. Muravjev ◽  
Irina S. Pozygun ◽  
Gennadiy M. Seropyan ◽  
Sergey A. Sychev ◽  
...  
Keyword(s):  
Thin Films ◽  
Current Density ◽  
Superconducting Devices ◽  
Single Crystal Substrate ◽  
Superconducting Thin Film ◽  
Elastic Stresses ◽  
Barium Copper ◽  
Crystal Substrate ◽  
Long Time ◽  
Yttrium Barium

The article is devoted to formation of superconducting thin films on the single-crystal substrate where areas with different values of the critical current density are, that is needed for fabrication of superconducting devices. The method is based on an establishment of elastic mechanical stresses on the substrate crystal under the nanosecond focused pulsed laser irradiation. On the irradiated substrate the superconducting thin film having auxiliary elastic stresses not till the area is over the irradiated section of the substrate is grown. At the same time the critical film current density is suppressed for required values are used to fabricate Josephson junctions. Observations for a long time demonstrate superconducting transport film properties are not varied significantly during the maintenance.

scholarly journals Donor/Acceptor Photovoltaic Cells Fabricated on p-Doped Organic Single-Crystal Substrates

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2068 ◽  
Author(s):  
Yusuke Yabara ◽  
Seiichiro Izawa ◽  
Masahiro Hiramoto
Keyword(s):  
Single Crystal ◽  
Photovoltaic Cells ◽  
Photocurrent Density ◽  
Iron Chloride ◽  
Single Crystal Substrate ◽  
Organic Single Crystal ◽  
Crystal Substrate ◽  
Donor Acceptor ◽  
Doping Technique ◽  
P Type

In this study, the operation of donor/acceptor photovoltaic cells fabricated on homoepitaxially grown p-doped rubrene single-crystal substrates is demonstrated. The photocurrent density is dominated by the sheet conductivity (σ□) of the p-type single-crystal layer doped to 100 ppm with an iron chloride (Fe2Cl6) acceptor. A 65 μm thick p-type rubrene single-crystal substrate is expected to be required for a photocurrent density of 20 mA·cm−2. An entire bulk doping technique for rubrene single crystals is indispensable for the fabrication of practical organic single-crystal solar cells.

Morphology and Dielectric Properties of Reactively Sputtered Aluminum Nitride Thin Films

1996 ◽  
Vol 449 ◽  
Author(s):  
A. G. Randolph ◽  
S.K. Kurinec
Keyword(s):  
Thin Films ◽  
Aluminum Nitride ◽  
Dielectric Strength ◽  
Film Structure ◽  
Force Microscopy ◽  
Atomic Force ◽  
Anion Vacancies ◽  
Lossy Dielectrics ◽  
Auger Electron Spectroscopic Analysis ◽  
Microscopy Examination

ABSTRACTAluminum nitride thin films (∼ 100 mn) have been deposited on silicon substrate by reactive sputtering using Al target in 1:1 Ar:N2 environment. The atomic force microscopy examination revealed continuous microcrystalline film structure. The Auger electron spectroscopic analysis show the presence of oxygen in the films. The annealing at 850 C in nitrogen is found to cause recrystallization and further oxidation of the films. The films can be characterized as lossy dielectrics with relative permittivity ∼ 10, higher than the bulk value of 8.9. Annealing the films is found to reduce anion vacancies and improve the dielectric strength within a range of a few MV/cm in these thin films.

Homoepitaxial Alignment of SrTiO3 Thin Films Prepared by Metallo-Organic Decomposition.

1991 ◽  
Vol 249 ◽  
Author(s):  
Gabriel Braunstein ◽  
Gustavo R. Paz-Pujalt
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Solid Phase ◽  
Single Crystal Substrate ◽  
Layer By Layer ◽  
Extrinsic Factors ◽  
Ion Channeling ◽  
Random Nucleation ◽  
Crystal Substrate ◽  
Organic Decomposition

ABSTRACTWe demonstrate the homoepitaxial growth of SrTiO3 prepared by the method of metallo-organic decomposition (MOD). Thin films of SrTiO3 are prepared by spin-coating and thermal decomposition of a solution of metallo-organic compounds, on single crystal, <100> oriented, SrTiO3 substrates and subsequently heat treated at temperatures ranging from 650°C to 1100°C for 30 minutes. Heat treatment at 1100°C results in the formation of single-crystal SrTiO3, perfectly aligned with respect to the underlying substrate.Ion-channeling analysis shows that the transformation to singlecrystal material proceeds epitaxially from the coating-substrate interface towards the surface of the sample. Transmission electron microscopy (TEM) studies of partially regrown samples reveal two distinct phases: an epitaxially aligned single-crystal phase, adjacent to the substrate, and a polycrystalline phase on top. On the basis of these observations, it is proposed that the crystallization of the MOD films involves the competition between two processes: layer-by-layer solid phase epitaxy and random nucleation and growth of crystallites. Layerby- layer epitaxy is the predominant crystallization mechanism unless it is inhibited by extrinsic factors like the contamination of the interface between the MOD film and the single-crystal substrate.

Preparation and Study of Strong Magnetoelectric Coupling on Multiferroic BaTiO3/La0.7Sr0.3MnO3 Bilayer Heterostructure

2011 ◽  
Vol 295-297 ◽  
pp. 2015-2019 ◽  
Author(s):  
Ting Xian Li ◽  
Ming Zhang ◽  
Zhou Hu ◽  
Kuo She Li ◽  
Dun Bo Yu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Coupling Parameter ◽  
Ferroelectric Properties ◽  
Laser Deposition ◽  
Low Dielectric Constant ◽  
Single Crystal Substrate ◽  
Low Dielectric ◽  
Bilayer Films ◽  
Voltage Coefficient ◽  
Crystal Substrate

The BaTiO3/La0.7Sr0.3MnO3((BTO/LSMO) bilayer films had been epitaxially grown on (001) oriented LaAlO3 (LAO) single crystal substrate by using pulsed laser deposition technique,. The measurements of electric and magnetic properties showed that the bilayer heterostructure possessed low dielectric constant (εr=263), high ferromagnetic curie temperature (Tc=317K), and natural ferromagnetic and ferroelectric properties. The magnetoelectric (ME) voltage coefficient for the bilayer heterostructures at room temperature was around 140 mV/cm.Oe, which is one magnitude order higher than others. The interface coupling parameter k between ferromagnetic and ferroelectric layers was 0.68.

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