材料期刊网

Mathematical Models and Computer Simulation of Nitrogen Concentration Profiles in Pulse Plasma Nitrided Layers

Mufu YAN , Qingchang MENG , Jihong YAN

材料科学技术（英）

Two materials, pure Fe and pure Al, were nitrided in a pulse plasma nitriding facility. The nitrogen profiles in surface layers and the surface phase structures of specimens nitrided at 500℃ for 8 h for Fe and for 6 h for Al were measured using the glow discharge spectrometry and an X-ray diffractometer, respectively. XRD results indicate that the compound layer with hcp crystal structure (AlN) was formed on the top of Al substrate. During nitriding of Fe, the compound layer growth conforms to parabolic law and the surface nitrogen concentration change little with increasing the nitriding time. The surface nitrogen content of nitrided Al specimens is less than theoretical value 34.17 wt pct of AlN. The mathematical models of nitrogen concentration profiles in the surface layer of nitrided Al specimen have been established based on the research of the kinetics of pulse plasma nitriding of Fe and the nitrogen concentration profiles were also simulated. Results show that the predicted curves agree basically with the experimental data.

关键词: Pulse plasma nitriding , null , null

Cu-Zr/ZrN薄膜体系的电阻率和纳米压入研究

白宣羽 , 汪渊 , 徐可为

稀有金属材料与工程

采用磁控溅射方法在Si(111)基片上沉积Cu-Zr/ZrN薄膜体系作为扩散阻挡层.通过比较Cu-Zr/ZrN薄膜体系和三元非晶(Mo,Ta,W)-Si-N的电阻率,同时比较Cu-Zr/ZrN薄膜体系和Ta,YaN的硬度,说明作为扩散阻挡层的材料的选取,应从整体性能上考虑,而不能仅仅考虑热稳定性等单一指标.

关键词: 非晶 , 电阻率 , 纳米压入 , 硬度

Studies of the g factors and the local structure for Ni3+in LaAl0.9Ni0.1O3, La0.75Y0.25Al0.99Ni0.01O3 and YAl0.9Ni0.1O3

Radiation Effects and Defects in Solids

The electron paramagnetic resonance g factors and the local structure for Ni3+ in LaAl0.9Ni0.1O3 (LAN), La0.75Y0.25Al0.99Ni0.01O3 (LYAN) and YAl0.9Ni0.1O3 (YAN) are theoretically studied from the perturbation formulas of the g factors for a 3d7 ion of low spin (S = 1/2) in tetragonally elongated octahedra. In these formulas, the contributions to the g factors from the tetragonal distortion, characterized by the tetragonal field parameters Ds and Dt are taken into account. According to the calculations, the ligand octahedra around Ni3+ are suggested to suffer 2% relative elongation along the [001] (or C4) axis due to the Jahn-Teller effect.

关键词: defect structures;electron paramagnetic resonance;crystal-fields and;spin Hamiltonians;Ni3+;LaAlO3;LaYAlO3;YAlO3;atomic screening constants;optical-spectra;paramagnetic-resonance;superconducting tapes;lattice-distortions;superposition model;scf;functions;cr3+ ions;crystals;epr

非微扰QCD和核遮蔽效应对K因子的影响

智海素 , 侯召宇

原子核物理评论 doi:10.3969/j.issn.1007-4627.2006.01.002

考虑非微扰量子色动力学物理真空夸克凝聚效应,计算了碳核与碳核在质心系能量分别为630和200 GeV时碰撞Drell-Yan过程的K因子,以及加入核遮蔽因子后非微扰效应对K因子的影响,并把计算结果与没有考虑夸克凝聚非微扰效应的K值进行了对比.结果表明,非微扰效应和核遮蔽效应对K因子影响很小.

关键词: K因子 , Drell-Yan过程 , 夸克凝聚 , 非微扰量子色动力学 , 核遮蔽效应