材料期刊网

Effect of Surface Modifications on the Magnetic Properties of Ni_0.5Zn_0.5Fe₂O₄ Nanoparticles

Wei Zhang Hongxia Wang Faling Zhang Zhengnan Qian Wenhui Su

材料科学技术（英文）

Two different silica sources have been used for the preparation of Ni_0.5Zn_0.5Fe₂O₄ /SiO₂ nanocomposites, and their effects on the particle size, crystallinity and the magnetic properties have been investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM) and physical property measurement system (PPMS). In both cases, Ni_0.5Zn_0.5Fe₂O₄ nanoparticles of 11 nm in mean particle size were well dispersed in silica matrix. The coercivity and the blocking temperature of Ni_0.5Zn_0.5Fe₂O₄  nanoparticles modified with the silicon coupling agent show little decrease, whereas the saturation magnetization increases obviously with respect to nanoparticles dispersed directly in silica matrix. It is considered that the decrease of the surface anisotropy resulting from the change in the surface coordination is responsible for the observed behavior.

关键词: Chemical synthesis , Silica , Magnetic properties , Ferrites

Jian ZHANG/Langhong Lou

材料科学技术（英文）

关键词:

Ion sputter erosion in metallic glass-A response to "Comment on: Homogeneity of Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass" by L-Y. Chen, Y-W. Zeng, Q-P. Cao, B-J. Park, Y-M. Chen, K. Hono, U. Vainio, Z-L. Zhang, U. Kaiser, X-D. Wang, and J-Z Jiang J. Mater. Res. 24, 3116 (2009)

Journal of Materials Research

The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.

关键词: room-temperature

Two-step magnetization in a spin-chain system on the triangular lattice: Wang-Landau simulation

Physical Review B

The Wang-Landau algorithm is used to study the thermodynamic and magnetic properties of triangular spin-chain system based on two-dimensional Ising model in order to understand the magnetic-order dynamics in Ca(3)Co(2)O(6) compound. The calculated results demonstrate that the equilibrium state of the rigid spins produces the two-step magnetization curve at low temperature even when the random-exchange term is considered. This work indicates that the four-step magnetization behavior observed experimentally must be due to the nonequilibrium magnetization.

关键词: calcium compounds;exchange interactions (electron);Ising model;magnetisation;thermodynamics;one-dimensional ca3co2o6;density-of-states;compound ca3co2o6;phase-diagram;proteins;crystal

改性SU8光刻胶的光学特性及其工艺

朱军 , 蒋宏民 , 陈翔 , 陈迪 , 刘景全

功能材料与器件学报 doi:10.3969/j.issn.1007-4252.2009.03.009

通过改变SU-8光刻胶中PAG浓度获得含不同PAG浓度的各种改性SU-8光刻胶,在对其光学性能以及最小曝光剂量的测定基础上研究改性SU-8光刻胶的光刻工艺,借助于改性SU-8光刻胶的合理设计以及背面曝光和正面曝光的结合应用提高多元材料复杂结构的集成制造能力.

关键词: 最小曝光剂量 , PAG , 集成制造

用于PDMS微芯片塑性成型的SU-8模具制作工艺的优化

陆振华 , 许宝建 , 金庆辉 , 赵建龙

功能材料与器件学报 doi:10.3969/j.issn.1007-4252.2008.03.015

PDMS是制作微流控芯片的主要材料.PDMS芯片制作的主要方法是模塑法,模塑法要求有良好的塑性成型模具.SU-8以其良好的微加工特性,目前已广泛应用于微机械结构的制作,也用于PDMS塑性成型的模具.本文根据模具的特殊性,如平整、无裂纹、可多次使用等要求,研究了影响SU-8模具结构与基底材料硅片的黏附性和形成裂纹的因素,优化了SU-8微模具加工工艺,在以0.5℃/min进行升降温、210 mJ/cm2的曝光剂量、200℃条件下硬烘30min条件下得到较好的SU-8模具,提供了一种快速、复用性高、低成本的PDMS微芯片塑性成型的SU-8模具的制作方法.

关键词: PDMS , 塑性成型 , SU-8模具 , 黏附性

静电纺丝制备SU-8光刻胶纳米纤维及图案阵列

刘俊 , 常梦洁 , 杜慧玲

高分子材料科学与工程 doi:10.16865/j.cnki.1000-7555.2016.04.023

利用静电纺丝和紫外光刻技术直接制备了不同结构的SU-8光刻胶纳米纤维薄膜及图案阵列.通过光学显微镜和扫描电子显微镜表征了纳米纤维的形貌、尺寸及结构.结果表明,通过改变SU-8光刻胶的黏度可形成不同直径和形貌的纤维结构,其中用SU-8 3010和SU-8 3050光刻胶制备的纳米纤维具有最优的形貌,其平均直径分别为470 nm和610nm.利用带有长方形缺口的铝箔和同轴电纺的方法分别制备了平行趋向和空心结构的纳米纤维.通过紫外光刻过程,可将SU-8纳米纤维加工成点阵、条状等不同形貌的图案阵列或结构,有望用作细胞培养研究的功能基底材料.

关键词: 静电纺丝 , 纳米纤维 , SU-8光刻胶 , 纤维图案

超厚SU-8负胶高深宽比结构及工艺研究

张金娅 , 陈迪 , 朱军 , 李建华 , 方华斌 , 杨斌

功能材料与器件学报 doi:10.3969/j.issn.1007-4252.2005.02.027

采用新型SU-8光刻胶在UV-LIGA技术基础上制备了各种高深宽比MEMS微结构,研究了热处理和曝光两个重要因素对高深宽比微结构的影响,解决了微结构的开裂和倒塌等问题;优化了SU-8胶工艺,从而获得了最大深宽比为27:1的微结构.

关键词: UV-LIGA技术 , SU-8胶 , 高深宽比微结构

激发双模SU(2)相干态的非经典性质

黄纯青 , 万广仁

量子电子学报 doi:10.3969/j.issn.1007-5461.2005.01.009

构造了激发双模SU(2)相干态|M,ξ;m〉=AMξma+mb+m|M,ξ〉,并用数值方法研究其非经典特性.结果表明,在双模SU(2)相干态的两场模同时增加光子后,两模光场仍然保持反关联特性,而且可以使光场对Cauchy-Schwartz不等式的破坏程度、光场的反聚束效应以及光子统计亚泊松分布等非经典特性得到加强.

关键词: 量子光学 , 非经典特性 , 激发 , 双模SU(2)相干态

手征SU(3)夸克模型与六夸克态的研究

张宗烨 , 余友文 , 袁秀青

原子核物理评论 doi:10.3969/j.issn.1007-4627.2000.01.003

用手征SU(3)夸克模型分析了(0s)6组态的六夸克态能量，结果表明手征SU(3)介子场可以对某些多奇异数的态提供较强的吸引作用．进一步用共振群方法研究了(ΩΩ)0+及(Ω )1+等多奇异数系统，得到(ΩΩ)0是一个深度束缚的双重态．

关键词: 夸克模型 , 六夸克态 , 手征对称性