Defect and Diffusion Forum Vol. 329

Abstract: The Problem of Solving Diffusion Equation with Free Boundary which Appeared during the Modeling of the Spherical Inclusion Formation Process within Spherical Domain Is Examined. the Algorithm and the Software Were Developed on the Basis of the Rothe Method in Combination with the Integral-Equations Method for their Numerically-Analytical Solution. Results of the Calculations Are Illustrated Graphically.

Abstract: An Oxide Ceramic-Based Composite in the Al₂o₃-Sio₂-Zro₂ (ASZ) System Was Developed and Investigated Using a Pressureless Sintering Route. the Effect of the Content of each Component and Sintering Temperature upon the Microstructure, Density, Hardness and Strength Was Studied. X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM) Were Used to Investigate the Phase Transformation Sequences of the ASZ Composite System. the Flexural Strength Was Measured Using Three-Point Bending Method on a Universal Testing Machine, while the Indentation Fracture (IF) Method Was Used to Determine the Fracture Toughness of the Composite. the Results Showed that, with Varying Zro₂ Content, Keeping the Silica Content Constant and the Alumina as a Matrix, Densification Tends to Decrease as the Content of Zirconia Increases from 20 Wt. % of the Composition. X-Ray Diffraction Peaks Indicated Fully Developed Alumina, Mullite and Zirconia Phases due to Solid-Phase Reaction and Liquid-Phase Sintering of the System. the Experimental Results Also Revealed that, for a Sintering Temperature of 1500°C, the Hardness Value Ranged from 12 Gpa to 14 Gpa and the Flexural Strength Was 420±31MPa.The Fracture Toughness (K_Ic) Was Also Reported to Be between 4.5 and 5.1 Mpa.m^1/2, for Samples Sintered at a Temperature of 14500C.

Abstract: Issues such as Tunneling, Leakage Currents and Light-Atom Penetration through the Film Are Threatening the Viability of Ultra-Thin Sio₂ as a Good Dielectric for Industrial and Electronic Devices and in Ceramic Technologies. in this Paper, the Effect of Zirconium-Doped Lanthanum Oxide Is Investigated in the Hope that this Material Can Be Used as a Good Gate Dielectric for the next Generation of CMOS (Complementary-Metal-Oxide-Semiconductor). Zirconium Lanthanum Oxide Nanocrystallites with General Formula of Zr_xla_1-xO_y Were Prepared by Using the Sol-Gel Method, such that the Zr Atomic Fractions in the Material Were in the Range of X = 5%, 20% and 50%. the Nanocrystallite’s Phases and Properties Were Characterized Using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) Techniques. Electrical Property Characterization Was Also Performed Using the Cyclic-Voltameter (C-V) Technique in TRIS Solution (pH = 7.3). C-V Measurements Show that Current through the TRIS Reduces at Higher Temperatures. Moreover, Elemental Qualitative Analysis Was Performed via Energy Dispersive X-Ray (EDX) Spectroscopy and Confirmed the above Claims.

Abstract: A Vanadium Pentoxide Sample with a Film Thickness of 75 Nm Has Been Thermally Evaporated on Unheated Glass Substrate Using V₂O₅ High Purity Powder. the Sample Was Subjected to a Subsequent Post-Deposition Annealing in Air at Different Temperatures for a Period of One Hour. the Optical Properties Were Studied by Transmittance and Reflectance Measurements. the Integrated Visible ,T_Vis, and Solar, T_Sol, Transmittance Were Calculated. the Spectral Behaviour of the Refractive Index as Well as the Absorption Coefficient before and after Post-Deposition Heat-Treatment Was Also Reported. X-Ray Diffraction Confirmed that the Film in the as-Deposited as Well as after Annealing up to 400 °C Is in the Amorphous State.

Abstract: The Solid Solution of ZrO₂ : Cdo Was Prepared by the Conventional Solid-State Reaction. Effect of Dopant Concentration on the Electrical Conductivity of ZrO₂ Was Studied for Different Compositions at Different Temperatures. the Conductivity Increases with the Addition of Cdo due to the Migration of Vacancies. the Conductivity Increases with Rise in Temperature up to 180°C and Thereby Decreases due to the Collapse of Fluorite Framework. A Second Rise in Conductivity at High Temperature beyond 460°C Is due to the Phase Transition of ZrO₂ from Monoclinic to Tetragonal. DSC, X Ray Powder Diffraction, Impedance Measurements and FTIR Spectral Studies Were Carried Out for Confirming the Doping Effect and Transitions in ZrO₂. the Addition of Cdo to Zro2 Shifted the Phase Transition of ZrO₂ to Higher Temperatures as Confirmed by the DSC Results. the Occurrence of Single Semi Circle with a Low Frequency Inclined Spike Indicates that the Conductivity Is Mainly due to the Movement of Oxide Ions.

Abstract: Atomic Layer Deposition (ALD) Offers the Key Benefits of Precise Deposition of Nanostructured Thin Films with Excellent Conformal Coverage. ALD Is Being Used in the Semiconductor Industry for Producing High-k (high Permittivity) Gate Oxides and High-K Memory Capacitor Dielectrics. Zno Has Attractive Properties for Various Applications such as Semiconductors, Gas Sensors and Solar Cells. in this Study, ZnO Thin Films Were Deposited via ALD Using Alternating Exposures of Diethyl Zinc (DEZ) and Deionized Water (H₂O) on Silicon Wafer (100). the Thin Films Were Analyzed Using X-Ray Diffraction (XRD), Ellipsometer and Atomic Force Microscope (AFM). the XRD Analysis Shows the Presence of ZnO Thin Films with a Hexagonal Wurtzite Structure. the Thickness of ZnO Thin Films Was Correlated with the Substrate Temperatures and Deposition Cycles. the Coating Thickness Was Found to Increase with the Increase of the Deposition Cycles, but it Decreased with the Increase of Deposition Temperature. the Nucleation and Growth Mechanism of Zno Thin Film Has Been Established. it Can Be Concluded that, the Growth Mechanism of Zno Films Is Strongly Dependent on the ALD Processing Conditions.

Abstract: The Temperature and Frequency Dependences of the Dielectric Constants () and Dielectric Loss (") Were Studied in Glassy Se₇₀Te₂₀Sn₁₀ Alloy in the Audio-Frequency Range below the Glass Transition Region. the Results Indicated that Dielectric Dispersion Occurred in Glassy Se₇₀Te₂₀Sn₁₀ Alloy. Well-Defined Dielectric Peaks Were Obtained in Glassy Se₇₀Te₂₀Sn₁₀ Alloy; these Are Rarely Observed in Chalcogenide Glasses. such Loss Peaks Were Not Observed in the Glassy Se_80-xTe₂₀Sn_x System in the past for Sn Concentrations of x ≤ 8. A Detailed Analysis of the Data Showed that the Results Could Be Explained in Terms of Dipolar Relaxation, with a Distribution of Relaxation Times, this Is Quite Expected in the Case of Chalcogenide Glasses.

Abstract: The Spin Hamiltonian Parameters (the G Factors and the Superhyperfine Parameters) for the Tetragonal [Fe(CN)₄Cl₂]^5- Complex in Nacl Are Theoretically Investigated from the Perturbation Formulas of these Parameters for a Low Spin (S=1/2) 3d⁷ Ion in Tetragonally Elongated Octahedra. this Impurity Center Is Attributed to the Substitutional Fe²⁺ (in the Form of [Fe(CN)₆]^4–) on Host Na+ Site Reduced by Capturing One Electron during the X-Ray Irradiation Process, with the Two Axial Ligands CN– Replaced by Two Cl–. since the Crystal Fields of the Axial Ligands Cl– Are Weaker than those of the Perpendicular Ligands CN–, the [Fe(CN)₄Cl₂]^5- Complex Exhibits a Tetragonally Elongated Octahedron. this System Shows the Low Spin S=1/2 of the Strong Crystal Field Case, which Is Unlike the High Spin S=3/2 of the Weak and Intermediate Crystal Field Case for Fe⁺ in Conventional Chlorides. the Theoretical Spin Hamiltonian Parameters Are in Reasonable Agreement with the Experimental Data, and the Results Are Discussed.