Key Engineering Materials Vol. 508

Abstract: Change in the Microstructure of the L1₀-Type Ordered β' Phase Precipitated in Ag-20Pd-12Au-14.5Cu Alloy (mass%) Subjected to Solution Treatment with Varying Solution Treatment Time Was Investigated. The Size of the β' Phase Is Found to Decrease with Increasing Solution Treatment Time and the Vickers Hardness of the Alloy after Solution Treatment Decreases. Experimental Observations Show that the Microstructural Change of the β' Phase Strongly Contributes to the Change in Vickers Hardness. In Addition, the Formation and Growth of the β' Phase Are Concluded to Be Affected by the Distribution of Elements through Solution Treatment.

Abstract: The Effect of Microalloying Elements and Compounds, such as Be, B, C, P, S, Ti, V, Cu, Zn, in, BN, VN, Mn₃N, LaN, MnS and Ti₄C₂S₂, Ranging in Amount from 0.005 to 0.2 at.%, on the α-Fe + FeLaSi Two-Phase Microstructure of a La(Fe_0.89Si_0.11)₁₃ as-Melted Specimen Was Investigated. The Addition of Mn₃N Was Found to Contribute to α-Fe Grain Refinement to a Certain Extent, but to Harm the Uniform Growth of the τ₁ Phase in the Stage of Subsequent Annealing.

Abstract: Mo and Cu Were Bonded Successfully by Means of Vacuum Diffusion Bonding. The Interfacial Structure of the Joints Was Studied by Scanning Electron Microscopy (SEM), Electron Probe Microanalysis (EPMA), Energy Dispersive X-Ray Spectrometer (EDS) and X-Ray Diffraction (XRD), the Mechanical Property Is Tested by Tensile Strength Measurement. The Results Showed that the Differentatoms Diffused to each other in the Bonding Process. A Mo-Cu Solid Solution Was Formed in the Joint and with No Intermetallic Compounds. The Tensile Strength of the Joint Increased with the Increasing of Temperature, however, while the Holding Time Increased, the Strength Increased in the First Stages and then Decreases. It Were Observed that the Fracture Mode of the Joints Was a Brittle Fracture.

Abstract: B-Axis-Oriented Bati2o5 Nanopillars Were Prepared on (100) Mgo Single Crystal Substrate by Laser Chemical Vapor Deposition Using Ba and Ti Dipivaloylmethanate Precursors. B-Axis-Oriented Bati2o5 Nanopillars Were Approximately 250–400 Nm in Width and 2.5 μm in Height. Deposition Rate of Bati2o5 Nanopillar Arrays Was about 75 μm H−1.

Abstract: Using the (100)-Oriented MgO Thin Film as the Buffer Layer, BaTi₂O₅ Films Were Deposited on Si(100) Substrates by Pulsed Laser Deposition under Various Oxygen Partial Pressures (P_O2). the Effects of P_O2 on the Crystal Phase, Orientation and Surface Morphology of the as-Deposited Films Were Investigated. Single-Phased Bati2o5 Films Were Obtained at P_O2 = 10-15 Pa, and the Preferred Orientation Changed from (710) to (020) with Decreasing P_O2. at P_O2 = 10 Pa, the BaTi₂O₅ Films with a Higher Degree of bItalic text-Axis Orientation and a Dense Texture Were Deposited on the Mgo(100)/Si(100) Substrates. The MgO Buffers Played an Important Role as Structural Templates for the Textured Growth of BaTi₂O₅ Films on Si Substrates.

Abstract: The Present Study Aims to Understand the Relation between the Nitridation and Indium-Composition of Ingan Grown on Sapphire Substrate Using the Metalorganic Vapor Phase Epitaxy through X-Ray Diffraction Reciprocal Space Mapping Measurements. In-Composition of InGaN on Nitrided Sapphire Substrate Increased to 13% which Is Higher than the Sample without Nitridation with 7%. Also, Flat Surface Was Observed in the Nitrided Sample. Two Times Larger in-Plane Strain Was Induced at the Nitired Sample. Ingan Grown on Low-Temperature Gan Buffer, however, Did Not Show Clear Effect of Nitridation. The Two Investigated Samples Showed Similar Indium Composition, Surface Flatness, and in-Plane Strain with and without Nitridation. Differences of Indium Incorporation and Relaxation of in-Plane Strain Were Attributed to the Effect of AIN Formed by Nitridation Process.

Abstract: Ba²TiO₄ and Ba₄Ti₁₃O₃₀ Thick Films Were Prepared by Laser Chemical Vapor Deposition Using Ba- and Ti-Dipivaloylmethanate Precursors. Single-Phase Ba₂TiO₄ Thick Films Were Obtained at 845–946 K and Ba/Ti Source Molar Ratio 2.4. Single-Phase Ba₄Ti₁₃O₃₀ Films Were Obtained at 944–1011 K and Ba/Ti Source Molar Ratio 0.38. Ba₂TiO₄ Thick Films Consisted of Truncated Grains, while Ba4ti13o30 Thick Films Had Shellfish-Like Grains. Ba₂TiO₄ and Ba₄Ti₁₃O₃₀ Thick Films Showed a Columnar Growth and their Deposition Rates Were 72 and 132 μm h⁻¹, Respectively.

Abstract: Our Recent Works on the Search for New Superconductors Using Soft-Chemical Techniques Are Reviewed. We Have Found New Mg-Intercalated Superconductors of Mg_xZrNCl and Mg_xHFNCl with Tc ~ 13 K and 25 K, Respectively. Moreover, we Have Succeeded in Preparing Bulk Samples of Hole-Doped (La,Ca)₂CuO₄ with the Nd₂CuO₄-Type, Namely, the so-Called T’-Type Structure by Reduction of (La,Ca)₂CuO₄ with the K₂NiF₄-Type, Namely, the so-Called T-Type Structure Using CaH₂ at a Temperature as Low as 300°C and Subsequent Oxidation. This Result Is in Contrast with the Synthesis of (La,Ca)₂CuO₄ with the K₂NiF₄-Type Structure by the Conventional Solid-State Reaction Method at a Temperature as High as ~1000°C.

Abstract: C-Axis-Oriented Y₂Ba₄Cu₇O_15-δ (Y247) Films Were Prepared on Multilayer-Coated Hasterolly Tape Substrate by Laser Chemical Vapor Deposition with Ultrasonically Nebulized Liquid Precursor. At a Low Precursor Concentration of 0.01 mol l⁻¹ and Deposition Temperature of 933 K, Single-Phase Y247 Film with Significant c-Axis Orientation Was Obtained. At a Precursor Concentration of 0.1 mol l⁻¹ and Deposition Temperature 983 K, a-Axis-Oriented YBa₂Cu₃O_7-δ (Y123) Was Codeposited with C-Axis Oriented Y247 Film.

Abstract: Transparent Conducting Antimony Doped Tin Oxide (ATO) Films Have Been Prepared on Quartz Substrate by Pulsed Laser Deposition (PLD) Technology. Despite of Extensive Researches of ATO Films Prepared by other Methods, the Study of PLD Technology Is Relatively few. PLD Technology Is Distinctive to Maintain the Elemental Components between the Targets and the Obtained Thin Flms under Optimal Conditions Contributing to Precise Control of Composition and Doping Ratio of ATO Films. The Effect of Sb₂O₃ Doping on the Electrical and Optical Properties of the ATO Films Was Investigated with Various Sb₂O₃ Doping Ratio (mol%) as 2, 4, 6, 8, 10 at 500 °C in an Oxygen Pressure of 8 Pa. The Results Suggest that the Electrical Resistivity Is Firstly Decreased and then Increased with the Increase of Sb₂O₃ Doping Ratio. When the Sb₂O₃ Doping Ratio Is about 6 mol%, the Optimal Electrical Resistivity Is 3.5×10-3 Ω.cm and the Average Optical Transmittance Is 83.1%. It Is Significant to Clarify the Impact Mechanism of Sb₂O₃ Doping Ratio to Get the Best Electrical and Optical Physical Properties. it Is Supposed that the Carrier Concentration Dominates at a Low Sb₂O₃ Doing Ratio while a Scattering Effect Is Performed at a High Sb₂O₃ Doing Ratio.