Bi Effect on the Microstructure and Dielectric Properties of SrTiO3 Thin Films

2006 ◽  
Vol 514-516 ◽  
pp. 245-249 ◽  
Author(s):  
Olena Okhay ◽  
Vitor M.X. Bergano ◽  
Ai Ying Wu ◽  
Paula M. Vilarinho
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Grain Size ◽  
Low Temperatures ◽  
Room Temperature ◽  
Sol Gel ◽  
Lattice Parameter ◽  
Dielectric Anomaly ◽  
Second Phase ◽  
Si Substrates

Crystalline (Sr1-1.5xBix)TiO3 (SBiT) thin films (0.002 ≤ x ≤ 0.5) were prepared by sol-gel on Pt/TiO2/SiO2/Si substrates. Cubic monophasic SBiT films were obtained for samples with x ≤ 0.167. For films with x ≥ 0.267 a second phase identified as Bi4Ti3O12 was observed. The lattice parameter of SBiT films increases with increasing Bi content, similar to the variation observed in SBiT ceramics. No obviously variation of the grain size with the Bi content was observed. The dielectric constant ε´ at room temperature increases with increasing of Bi concentrations up to x ≤ 0.1. The loss tangent of Bi doped SrTiO3 films is approximately 0.05 and lower than undoped ST films at 10kHz. The higher values of ε´ of Bi doped ST films with x=0.1 and x=0.167 in comparison with undoped films may suppose the appearance of a dielectric anomaly at low temperatures, which will be dependent on the Bi content.

VERY HIGH TUNABILITY OF BaSnxTi1-xO3 FERROELECTRIC THIN FILMS DEPOSITED BY SOL-GEL

2011 ◽  
Vol 04 (01) ◽  
pp. 49-52 ◽  
Author(s):  
MANUEL MASCOT ◽  
DIDIER FASQUELLE ◽  
JEAN-CLAUDE CARRU
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Spin Coating ◽  
Room Temperature ◽  
Sol Gel ◽  
Si Substrates ◽  
High Tunability ◽  
Annealing Conditions ◽  
Record Value ◽  
Very High

Ba(Sn0.02Ti0.98)O3 thin films (BTS) were prepared by sol-gel route and deposited by spin-coating on commercial Pt/Ti/SiO2/Si substrates. By modifying the annealing conditions from 750°C for 1 h to 950°C for 15 min, the grain size increased from 60 nm to 110 nm due to the increased driving force. The dielectric permittivity ε′ and tunability nr are correlated with the grain size: these parameters increase with the grain size. At room temperature for the BST film annealed at 950°C, a record value of 76% of tunability is obtained at 10 kHz. This very high value of tunability makes BaSnTiO 3 a very good candidate for tunable devices.

Influence of Strontium Concentration on the Microstructure and Electrical Properties of Sol-Gel Derived Barium Strontium Titanate Thin Films

1996 ◽  
Vol 433 ◽  
Author(s):  
M.C. Gust ◽  
L.A. Momoda ◽  
M.L. Mecartney
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Grain Size ◽  
Barium Strontium Titanate ◽  
Sol Gel ◽  
Heat Treating ◽  
Si Substrates ◽  
Barium Strontium ◽  
Average Grain Size ◽  
Alkoxide Precursors

AbstractBaxSrl−xTiO3 thin films with varying Sr concentration were prepared on Pt coated Si substrates using methoxypropoxide based alkoxide precursors. Films were crystallized by heat treating at 700°C for 30 minutes in an oxygen atmosphere after deposition of each layer. Film thickness ranged from 230 to 260 nm. No evidence of tetragonality was observed in any of the compositions. Films with higher Sr concentrations had a larger average grain size, larger grain size distribution, and increased (111) orientation on (111) oriented Pt. The highest dielectric constant of ˜400 was found for Ba 0.5Sr0.5TiO3, although no direct correlation could be made between the composition and dielectric properties.

Structural, Magnetic, and Electrical Properties of BiFe1-xMnxO3 Thin Films

2009 ◽  
Vol 1199 ◽  
Author(s):  
Danilo G Barrionuevo ◽  
Surinder P Singh ◽  
Maharaj S. Tomar
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Magnetic Measurements ◽  
Sol Gel ◽  
Ion Concentration ◽  
Ferromagnetic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Sol Gel Process

AbstractWe synthesized BiFe1-xMnxO3 (BFMO) for various compositions by sol gel process and thin films were deposited by spin coating on platinum Pt/Ti/SiO2/Si substrates. X-ray diffraction shows all the diffraction planes corresponding to rhombohedrally distorted perovskite BiFeO3 structure. The absence of any impurity phase in the films suggests the incorporation Mn ion preferentially to Fe site in the structure for low concentration. Magnetic measurements reveal the formation of ferromagnetic phase at room temperature with increased Mn substitution. On the other hand, ferroelectric polarization decreases with increasing Mn ion concentration. Raman studies suggest the dopant induced structural distortion.

Electrical Properties Optimization of Ba0.9Sr0.1TiO3 Thin Films Deposited by Sol-Gel

2011 ◽  
Vol 277 ◽  
pp. 1-10 ◽  
Author(s):  
D. Fasquelle ◽  
M. Mascot ◽  
J.C. Carru
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Electrical Properties ◽  
Annealing Time ◽  
Remnant Polarization ◽  
Sol Gel ◽  
Si Substrates ◽  
Annealing Temperatures ◽  
Annealing Conditions ◽  
Average Size

This paper reports a study of Ba0.9Sr0.1TiO3films deposited on Pt/Ti/SiO2/Si substrates. The annealing temperatures were 750°C, 850°C and 950°C. An increase of the average size of grains was observed, from 60 nm at 750°C to 110 nm at 950°C, as well as an increase of the dielectric constant, remnant polarization and tunability. When the annealing time was decreased from 1 hour to 15 min, the dielectric constant and remnant polarization values have been increased. The optimized annealing conditions (950°C for 15 min) give the following results: εr= 780 and tgδ = 0.01 at 100 kHz, Pr = 13 µC/cm², Ec = 63 kV/cm and a tunability of 55%.

Hydrogen Gas Sensing Characterizations Based on Nanocrystalline SnO2 Thin Films Grown on SiO2/Si and Al2O3 Substrates

2017 ◽  
Vol 268 ◽  
pp. 244-248
Author(s):  
Abu Hassan Haslan ◽  
Imad Hussein Kadhim
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Gas Sensing ◽  
Sol Gel ◽  
Hydrogen Gas ◽  
Rutile Structure ◽  
Nanoparticle Distribution ◽  
Si Substrates ◽  
Coating Method ◽  
Different Temperatures

High-quality nanocrystalline (NC) SnO2 thin films were grown on SiO2/Si and Al2O3 substrates using sol–gel spin coating method. The structural properties, surface morphologies and gas sensing properties of the NC SnO2 were investigated. XRD measurements showed a tetragonal rutile structure and the diffraction peaks for NC SnO2 thin films grown on Al2O3 substrates outperformed those of NC SnO2 films grown on SiO2/Si substrates. The surface morphology of the annealed SnO2 thin films at 500 °C appeared as polycrystalline with uniform nanoparticle distribution. Hydrogen (H2) gas sensing performance of the NC SnO2 was examined for H2 concentrations ranging from 150 ppm to 1000 ppm at different temperatures (room temperature, 75 and 125 °C) for over 50 min. The room temperature sensitivities for H2 gas sensors based on NC SnO2 thin films grown on Al2O3 and SiO2/Si substrates was 2570% and 600%, respectively upon exposure to 1000 ppm of H2 gas. While the sensitivity values at 125 °C increased to 9200% and 1950%, respectively.

Preparation of BaTiO3 and PbTiO3 thin Films on BaPb3 Substrates by the SOL-GEL Method and Their Properties

1992 ◽  
Vol 271 ◽  
Author(s):  
M. KuWabAra ◽  
T. Kuroda ◽  
S. Takahashi ◽  
T. Azuma
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Lead Titanate ◽  
Room Temperature ◽  
Sol Gel ◽  
Ceramic Substrates ◽  
Gel Method ◽  
Sol Gel Method ◽  
Ceramic Thin Films ◽  
Titanate Lead

ABSTRACTBarium titanate, lead titanate and barium-lead titanate thin films were prepared by the sol-gel method using metal alkoxides on metallic conducting BaPbO3 ceramic substrates. Thin films were deposited on the polished surfaces of the substrates by spin coating solutions containing Ba(OC2H4OCH3)2, Pb(OCOCH3)2 and Ti(O-iC3H7)4 and methoxyethanol. The gel films were then fired at appropriate temperatures to yield ceramic thin films. A 0.50 µm-thick BaTio3 film showed a dielectric constant of 280 and tan ° of 3% at 1kHz with no distinguishable peak of dielectric constant at any temperature between 20°C and 200°C. Both PbTiO3 (0.75 µm thick) and Ba0.7Pb0.3 (0.2 µm thick) films, on the other hand, showed a distinguishable peak of dielectric constant at their Curie point with a rather deformed P-E hysteresis loop at room temperature.

The Effect of Annealing on the Cu Distribution and AI2Cu Precipitation in Ai(Cu) Thin Films

1993 ◽  
Vol 309 ◽  
Author(s):  
E.G. Colgan ◽  
K.P. Rodbell ◽  
D.R. Vigliotti
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Grain Boundaries ◽  
Low Temperatures ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Precipitate Morphology ◽  
Electromigration Lifetime ◽  
Bamboo Structure ◽  
Anneal Temperature

AbstractThe Cu distribution in AI(Cu) thin films has been examined in blanket and patterned samples as a function of annealing. The Cu concentration in the Al grains, measured at room temperature, closely follows the solubility at the anneal temperature when a high cooling rate is used (-100 or -200°C/min) from the annealing temperature. With fine lines, the room temperature Cu concentration follows the solubility at the anneal temperature only at low anneal temperatures, ≤350°C. With higher temperatureannealing, >400°C, the room temperature Cu concentration in the Al grains was substantially less than the solubility at the anneal temperature. These differences are attributed to the smaller grain size in fine lines, which reduces the distance to grain boundaries. With blanket films, the Θ-phase (Al2Cu) precipitate morphology depends on the Al grain size and annealing temperature. With small Al grains (100-300 nm), the Θ particles are small (100-200 nm) and round whereas with large Al grains (0.5-2μm), the precipitates are long and irregularly shaped. The morphology of the Θ precipitates is constrained by the Al grain size. With fine lines, having a bamboo structure, the Θ precipitates are “wedge” shaped along grain boundaries or span the width of the line. The electromigration lifetime was found to depend strongly on the heat treatment used, an increase of 3X in lifetime was obtained for samples rapidly cooled from a temperature above the solvus curve as compared with samples subjected to additional aging at low temperatures. This is believed to be dueto the different concentrations of Cu in solution and to the size and distribution of Θparticles in the patterned lines.

Enhanced the Dielectric and Tunable Properties of BZNT Thin Films through Adjusting Annealing Process

2012 ◽  
Vol 252 ◽  
pp. 211-215
Author(s):  
Xiao Hua Sun ◽  
Shuang Hou ◽  
Zhi Meng Luo ◽  
Cai Hua Huang ◽  
Zong Zhi Hu
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Loss ◽  
Annealing Temperature ◽  
Rf Magnetron Sputtering ◽  
Annealing Process ◽  
Si Substrates ◽  
Tunable Properties

Bismuth zinc niobate titanium (Bi1.5Zn0.5 Nb0.5Ti1.5O7) (BZNT) thin films were deposited on PtTiSiO2Si substrates by radio frequency (rf) magnetron sputtering. The microstructure, surface morphology, stress, dielectric and tunable properties of thin films were investigated as a function of initial annealing temperature. It’s found that high initial annealing temperature increases the grain size, dielectric constant and tunability of BZNT films simultaneously and decreases the tensile stress in films. The BZNT thin film annealed from 500 °C to 700 °C shows the highest FOM value of 45.67 with the smallest dielectric loss and upper tunability.

Physical properties of spinel iron oxide thin films

1988 ◽  
Vol 3 (2) ◽  
pp. 344-350 ◽  
Author(s):  
C. Ortiz ◽  
G. Lim ◽  
M. M. Chen ◽  
G. Castillo
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Size ◽  
Physical Properties ◽  
Room Temperature ◽  
Lattice Parameter ◽  
Infrared Transmission ◽  
Transmission Properties ◽  
Annealing Conditions ◽  
Deposition Conditions

This paper describes the complexity of the spinel iron oxides in thin-film configuration. First, the experimental deposition conditions are determined for the parameters of substrate temperature and oxygen flow such that only the “Fe3O4” phase is formed. Then a study is made of how the structural (grain size, lattice parameter, texture), magnetic (M), and optical (visible and infrared transmission) properties of the films depend on the deposition and postdeposition (air annealing) conditions. The experimental deposition region is defined where the films have the most similar physical properties to bulk Fe3O4 and subsequently, after annealing, to bulk gamma Fe2O3. Finally, a discussion is presented of a model that accounts for the anomalous, low values of the magnetic moment for the samples deposited at room temperature. The model proposes an overpopulation of the iron tetrahedral A sites.

The Dielectric Tunability of Fe-Doped Pb0.3Sr0.7TiO3 Thin Films Prepared by Sol-Gel Method

2011 ◽  
Vol 399-401 ◽  
pp. 958-962
Author(s):  
Xiao Hua Sun ◽  
Shuang Hou ◽  
Xiu Leng Li ◽  
Tian You Peng ◽  
Xing Zhong Zhao
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Dielectric Loss ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method ◽  
Force Microscopy ◽  
Si Substrates ◽  
Fe Content ◽  
Metal Insulator Metal

Fe-doped Pb0.3Sr0.7TiO3 (PST) thin films have been fabricated on Pt/Ti/SiO2/Si substrates with sol–gel method. The structure and surface morphology of Fe-doped PST thin films were investigated as a function of Fe concentration by x-ray diffraction (XRD) and atomic force microscopy (AFM). The dielectric measurements were conducted on metal-insulator-metal capacitors at the frequency from 100 Hz to 1M Hz at room temperature. It’s found that the dielectric constant, dielectric loss and tunability of Fe-doped PST films decreased with the increase of Fe content. The effects of Fe doping on the microstructure, dielectric and tunable properties of thin films were analyzed. Though the undoped PST thin film exhibited the highest dielectric constant of 2011 and the largest tunability of 76%, the 6 mol% Fe doped PST thin films had the highest figure of merit (FOM) of 17.9 for its lowest dielectric loss.

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