Low temperature processed highly conducting, transparent, and wide bandgap Gd doped CdO thin films for transparent electronics

Gadolinium (Gd) doped cadmium oxide (CdO) thin films are grown at low temperature (100 °C) using pulsed laser deposition technique. The effect of oxygen partial pressures on structural, optical, and electrical properties is studied. X-ray diffraction studies reveal that these films are polycrystalline in nature with preferred orientation along (1 1 1) direction. Atomic force microscopy studies show that these films are very smooth with maximum root mean square roughness of 0.77 nm. These films are highly transparent and transparency of the films increases with increase in oxygen partial pressure. We observe an increase in optical bandgap of CdO films by Gd doping. The maximum optical band gap of 3.4 eV is observed for films grown at 1 × 10⁻⁵ mbar. The electrical resistivity of the films first decreases and then increases with increase in oxygen partial pressure. The lowest electrical resistivity of 2.71 × 10⁻⁵ Ω cm and highest mobility of 258 cm²/Vs is observed. These low temperature processed highly conducting, transparent, and wide bandgap semiconducting films could be used for flexible optoelectronic applications.     

Low temperature pulsed laser deposition of textured γ′-Fe4N films on Si (1 0 0)

Low-temperature reactive pulsed laser deposition (PLD) was used to prepare iron nitride films. The textured γ′-Fe₄N films with (0 0 1)-orientation were deposited on Si (1 0 0) substrate with Fe buffer layer at a substrate temperature as low as 150 °C. The (0 0 1)-oriented γ′-Fe₄N film grew on the Fe buffer layer with a 3.5-nm thick amorphous interlayer, which eliminated the lattice mismatch stress between them. The films showed a columnar granular morphology with an average lateral grain size of approximately 110 nm. The films exhibited good soft magnetic properties with a high in-plane M_r/M_s value of 0.84. The magneto-optic Kerr effect results indicated an in-plane magnetic isotropy and confirmed the high remnant ratio of the γ′-Fe₄N films.     

Effect of lanthanum doping on linear and nonlinear-optical properties of Bi3TiNbO9 thin films

Lanthanum doped Bi₃TiNbO₉ thin films (LBTN-x, La³⁺ contents x = 5%, 15%, 25% and 35 mol.%) with layered perovskite structure were fabricated on fused silica by pulsed laser deposition method. Their linear and nonlinear optical properties were studied by transmittance measurement and Z-Scan method. All films exhibit good transmittance (>55%) in visible region. For lanthanum doping content are x = 5%, 15% and 25 mol.%, the nonlinear absorption coefficient of LBTN-x thin films increases with the La³⁺ content, then it drops down at x = 35 mol.% when the content of La³⁺ in (Bi₂O₂)²⁺ layers is high enough to aggravate the orthorhombic distortion of the octahedra. We found that, 25 mol.% is the optimal La³⁺ content for LBTN-x thin films to have the largest nonlinear absorption coefficient making the LBTN-x film a promising candidate for absorbing-type optical device applications.     

A novel method to synthesis magnetic thin film of iron oxide

A novel method is used to deposit iron oxide thin film. Frozen iron acetate is used as a target for pulsed laser deposition of iron oxide thin film. KrF excimer laser having wavelength of 248 nm with pulsed duration of 20 ns is used to deposit the film. Structural characterizations were performed using X-ray diffraction and atomic/magnetic force microscopy. The X-ray diffraction patterns confirmed the polycrystalline nature of α-Fe₂O₃. Temperature dependence magnetic measurements in zero field cooled showed the presence of blocking temperature at ∼60 K. The magnetic measurements revealed the existence of superparamagnetic behavior above blocking temperature and freezing of magnetic moments arising from uncompensated surface spins below blocking temperature.     

激光重熔超音速火焰喷涂Cr3C2—25％CrNi层的数值分析及实验验证

利用ANSYS软件建立激光重熔超音速火焰喷涂（HVOF）层的有限元模型,进行温度场的仿真模拟,考察激光重熔工艺参数对温度场分布的影响,结果表明单向匀速扫描过程中引起的热量积聚,通过双向扫面、变速扫描等方式可以解决。通过实验验证了模型的有效性,分析发现激光重熔能有效改善超音速火焰喷涂涂层的质量,根据仿真结果和试验可确定合理的激光重熔工艺参数。最后,讨论了激光工艺参数对涂层组织和性能的影响。     

激光焊接技术在梅钢冷轧厂酸轧线上的应用

主要介绍了德国Miebach激光焊机在现代化钢铁厂酸轧线产品生产工艺中的技术应用情况。从该激光焊机的设备结构、工艺流程、工艺参数、带钢焊缝质量试验分析和技术创新等5个方面进行了详细的介绍和深入的剖析,论述了该设备的技术特性与先进性。     

表面熔敷技术概述

针对现代工业发展的需要,主要对感应熔敷技术、激光熔敷技术、堆焊熔敷技术、热喷涂技术等表面熔敷技术的定义、特点、应用进行了概括说明,对表面熔敷技术中涉及的工艺、所用材料、所需条件进行了阐述。     

集装箱波纹板折线焊缝跟踪的研究

为了实现类似于集装箱波纹板形式的焊缝自动焊接,采用了一种四自由度、可在波纹板折线位置处改变焊枪角度的直线轨道式焊接机器人.设计了空间漫反射激光测距传感器检测波纹板的折弯位置,利用TMS320LF2407A型DSY产生PWM脉冲信号驱动传感器芯片线阵CCD,并采集传感器输出信号,通过串行口传输到上位计算机.通过数字滤波器...     

NAK80模具钢表面激光熔覆Ni基碳化钨合金涂层的组织和性能

采用激光熔覆技术,在NAK80模具钢表面制备了Ni基碳化钨合金涂层.研究了激光熔覆涂层的组织结构特点及形成规律,测试分析了其显微硬度的分布特征.结果表明:涂层与基体之间呈良好冶金结合,熔覆层组织主要由树枝晶Cr<,23>C<,6>、未熔碳化钨颗粒相、γ-Ni固溶体及少量分布于固溶体中的NiCr和CrB<,2>相组成;涂...     

1Cr17Ni2不锈钢表面激光熔覆层的微观组织和性能研究

在1Cr17Ni2不锈钢表在进行激光熔覆.分析了激光熔覆单道熔覆层热裂纹形成机理以及微观组织分布特征;对熔覆层多道多层搭接进行了实验,采用优化的工艺参数堆覆制造了无裂纹、气孔等缺陷的致密薄壁件试样,对试样横截面微观组织特征和硬度分布规律进行了分析.分析表明,激光熔覆组织成分均匀,组织致密、具有快速熔凝组织特征并且性能优...