Papers by Keyword: CSD

Abstract: We have grown a SrTiO₃ thin film from strontium acetate and titanium isopropoxide using chemical solution deposition (CSD) method using a spin coater, and furnace annealed with a temperature of 850°C for 8 hours. We have assessed the thin-film frequency, magnetic field, and electric charges using LCR meter and light intensities of 0 (dark), 4000, 8000, 12000 lux. From the data of LCR meter, it can be measured and see the relationship between the current and the angular velocity will be decreased. Also, the results of the measurements obtained the relationship between magnetic fields and angular velocity is reduced as well. Therefore, we can be assumed the higher the intensity of light shall lower the magnetic properties.

Abstract: Barium Strontium Titanate (Ba_xSr_1-xTiO₃) thin films have been synthesized for mole fraction 𝑥 = 0; 0.125; 0.25; 0.375; and 0.500 using Chemical Solution Deposition (CSD) method. The thin film was grown on p-type silicon (100) substrate using spin coating technique and annealed at 850 ^∘C for 8 hours with an increasing rate of 1.67 ^∘C/minute. The BST thin film was characterized using LCR meter to obtain data on frequency, charge, and electrical current. We also model the occurrence of vicinity magnetic induction around the thin film produced by the current flow in the BST thin film. The electrical and magnetic induction response of BST thin film with variation of mole fraction are presented here.

Abstract: BST thin films have been grown by Chemical Solution Deposition (CSD) method on the substrate of Pt/Si. The fabrication of BST doped by Fe have been successfully using spin coater with 4000 rpm during 30 second. Annealing process use the holding time at 3 hours, the heating rate at 5°C/min and temperature at 800°C. The ratio of Ba_0.8Sr_0.2TiO₃ molar and Fe variant dopant (0%, 1%, 3%, and 5%) were characterized by X-Ray Diffraction (XRD) and obtaining results that show the peak shift due to variations dope. The peak shifted to the right for each increment Fe dopant. Results of addition Fe dopant also cause a differences in the magnitude of Full Width at Half Maximum (FWHM) and lattice parameters on BST ferroelectric materials. Other characterize that has been done by Scanning Electron Microsopy (SEM), it is show the thickness of the material. The resulting lattice parameters with the General Structure Analysis System (GSAS) software analysis showed that a thin films of BST and BSTF have a tetragonal structure because it has a value of a=b≠c and α=β=γ=90⁰. Based on SEM characterization, the thickness of thin film is about 330 nm.

Abstract: The influence of Mn/Ga solution on the characteristics of solid composition and microstructure of GaN:Mn thin film was studied. GaN:Mn thin films were deposited on Si (111) substrate by the Chemical Solution Deposition (CSD) method using the spin coating technique. Variations of the Mn/Ga mole fraction were 4%, 6%, 8%, and 10% respectively. The GaN:Mn thin films were then heated at a temperature of 900°C for 2 hours in an N₂ environment with a constant flow rate of 120 sccm. Atomic composition, crystal structure, and surface morphology of GaN:Mn thin films were characterized using X-Ray Diffraction (XRD), Energy Dispersive of X-ray (EDX), and Scanning Electron Microscope (SEM). EDX results showed that the larger the Mn/Ga mole fraction solution, the higher the Mn At percentage is. The correlation of At Mn percentage and Mn/Ga solution mole fraction is represented by the formula y = 0.023x³ - 0.352x² - 1.742x -2.81. All of the GaN:Mn thin films still have nitrogen vacancy, carbon impurity and maintain the wurtzite polycrystalline structure. Lattice parameter a, which is in the range of 3.2077Å – 3.2621Å, and lattice parameter c, which is in the range of 5.1094Å – 5.3038Å, depend on Mn atomic percentage of the film. The Root Mean Square (RMS) of GaN:Mn thin film surface roughness is in the range of 15.3nm – 29.90nm. The grain size for the 6% Mn/Ga mole fraction thin film is homogeneous.

Abstract: Coupling between the vibration frequencies and the unsteady aerodynamic will reduce the flutter speed and ride quality through the aerodynamic heat transfer. As the flight speed improved, the aeroelastic analysis has become an essential means of aircraft design. The method of aero-thermo-elastic (ATE) analysis is coupled with aircraft aeroelastic analysis and thermal deformation, and is more realistic reflection of the actual flight of the aircraft. In this paper, an ATE analysis of aircraft adopted by computational fluid dynamics/computational structural dynamics (CFD/CSD) methods, and compared with the traditional analysis, to provide analytical tools for the supersonic aircraft design.

Abstract: In this paper, a design of a digital decimation filter which has a output of 24 bits for high-precision 4-ordes Σ-Δ ADC is proposed. The digital decimation filter includes a CIC filter, a compensation filter and a half band filter. The over-sampling rate of the digital decimation filter is 256, the cutoff frequency is 1kHz, the coefficient of the pass-band ripple is -0.25dB, the stop-band attenuation is -162dB, simulation results using Matlab and modelsim are correct, the result of the FPGA verification shows that the design meet the requirement of the high-precision 4-ordes Σ-Δ ADC.

Abstract: A numerical analysis method for fluid-structure interaction (FSI) to analyze engine blades dynamic response was presented. Fluid-structure interaction is an important research field. It is mostly studies the interaction between the influence upon the fluid by the deformation of the solids, the important characteristic of fluid-solid interaction mechanics is the fluid-solid interaction between the both phase mediums. The solutions of strongly coupling and weakly coupling were discussed firstly in this paper. We compared the advantages and disadvantages of the strongly coupling and weakly coupling. And using numerical analysis method based on weakly coupling, we established a fluid-solid interaction control equation taking solid and fluid as a unified mathematical model. And we study about blades deformation and displacement under the action of air loading in engine. Using computational structural dynamics (CSD) calculate the displacements of blades, and using computational fluidic dynamics (CFD) calculate the pressures of blades, completing the fluid-structure interaction analysis in engine blades by iterating this two values(the displacements and the pressures) until the computational convergence solution is obtained. At the end of this paper, the model of fluid-structure interaction and the simulate procession of the numerical analysis method were presented. Based on the analysis, the simulation result is qualitatively discussed referring to the factual conditions of the engine for validating the feasibility of analysis method.

Abstract: The microstructure and electrical properties of P(VDF-TrFE)/Bi_3.5Nd_0.5Ti₃O₁₂ bi-layer composite ferroelectric thin films deposited on Pt/Ti/SiO₂/Si using two successive spin coatings were investigated. It shows the pores in Bi_3.5Nd_0.5Ti₃O₁₂ (BNT) films were effectively suppressed by the presence of P(VDF-TrFE) copolymer films by SEM. The ferroelectric, leakage and dielectric properties of the thin films with different thickness ratio of P(VDF-TrFE) and BNT thin films were measured. With increasing the thickness of P(VDF-TrFE), the remnant polarization, coercive electric field, leakage current density and dielectric constant of thin films were all decreased (except pure P(VDF-TrFE) thin film). Results indicate that the key electrical properties were improved effectively by a little loss of the remnant polarization, which infers potential application in the filed of ferroelectric memory.

Abstract: Epitaxially grown (Ba,Sr)TiO3 thin films were prepared on platinum-coated silicon substrate by sol-gel method using a (Ba,Sr)TiO3 sol derived from Ba(CH3COO)2, Sr(CH3COO)2 and Ti(O-i-C3H7)4. The morphology of the films was found to depend on the annealing condition. A columnar structure was obtained for (Ba,Sr)TiO3 thin film by annealing at 800 °C and a columnar grain was found to be single crystal by transmission electron microscope (TEM). The columnar grown film exhibits a preferred (111) orientation that follows the (111) orientation of Pt substrate. Measurement of the C-V in MFM was configured in order to demonstrate good dielectric properties. Obtained films showed high voltage tunability.

Abstract: This paper describes the deposition of PZT/oxide electrode thin film capacitors on Si(100) substrate with a CSD (Chemical Solution Deposition). Highly (100)&(001)-oriented SRO/LNO electrode films with a perovskite structure were obtained by the annealing at 700 °C from a precursor solution of Sr and RuCl3·2H2O for SRO and from a precursor solution of La(NO3)3 and Ni(CH3COO)2 for LNO. In addition, highly (100)&(001)-oriented PZT/oxide electrode capacitor were deposited on SRO/LNO/Si substrate by annealing at 650 °C, showing a good ferroelectricity of Pr=22μC/cm2 and Ec=55 kV/cm. In addition, the resultant PZT/oxide electrode thin film capacitors exhibited no fatigue up to 108 switching cycles.