Physics Letters A
In this Letter, using the first-principles full-potential linearized augmented plane-wave (FP-LAPW) method, we extend the electronic structure and magnetism studies on zinc-blende structure of II-V compounds MX (M = Ca, Sr, Ba; X = N, P, As) [M. Sieberer, J. Redinger, S. Khmelevskyi, P. Mohn, Phys. Rev. B 73 (2006) 024404] to the rock-salt structure. It is found that, in the nine rock-salt compounds, only alkaline-earth nitrides CaN, SrN and BaN exhibit ferromagnetic half-metallic character with a magnetic moment of 1.00 mu(B) per formula unit. Furthermore, compared with the zinc-blende structure of CaN, SrN and BaN, the rock-salt structure has lower energy, which makes them more promising candidates of possible growth of half-metallic films on suitable substrates. (c) 2007 Elsevier B.V. All rights reserved.
关键词:
half-metallic ferromagnetism;alkaline-earth metals;first-principles;calculations;room-temperature
李国民
,
李俊凤
,
刘静芝
,
吴庸烈
应用化学
doi:10.3969/j.issn.1000-0518.2006.03.001
考察了一系列共混改性聚酰亚胺(PI)膜的亲水性、共混溶液的表观粘度,结果表明,随着季胺盐(BAN)量的增加,膜的亲水性增强,溶液的表观粘度增大,出现了盐增粘现象.测试了一系列共混改性中空纤维膜组件的除湿性能,增大压力和增加吹扫气流量,对组件除湿十分有利,尽管组件的除湿性能并不是一直随着膜的亲水性增强而提高,但是适当增加亲水性盐(BAN),膜的除湿性能会得到有效改善.
关键词:
共混改性
,
聚酰亚胺
,
季胺盐
,
亲水性
,
除湿
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
Journal of Physics-Condensed Matter
Recent theoretical studies indicate that metastable rocksalt CaN, SrN, and BaN exhibit half-metallic ferromagnetism (Volnianska and Boguslawski 2007 Phys. Rev. B 75 224418; Gao et al 2008 Phys. Lett. A 372 1512), and further experiments confirm the existence of self-assembled metastable CaN nanostructures (Liu et al 2008 Surf. Sci. 602 1844). We here use the first-principles method based on density functional theory to investigate the structural, electronic, and magnetic properties of the (111) surfaces of CaN and SrN and the interfaces of CaN/InN(111) and SrN/GaP(111). The surface stability from the calculated surface energy indicates that the N-terminated (111) surface is more stable than the Ca (Sr)-terminated (111) surface in the N-rich environment. For CaN and SrN, both anion-and cation-terminated (111) surfaces preserve the half-metallic characteristics of the bulk. Interfacial studies indicate that the half-metallicity of bulk CaN is retained in two of the four possible configurations of the CaN/InN(111) interface, while for the interface of SrN/GaP(111) only one interfacial configuration shows half-metallicity. Furthermore, we assess the interfacial adhesive strength for all the possible different configurations of the interfaces studied here by calculating the interface adhesion energies.
关键词:
molecular-beam epitaxy;room-temperature;ferromagnetism;1st-principles
蒋洪
,
余会成
,
韦贻春
,
钟莲云
,
韩燕燕
涂料工业
为了提高6063铝合金的防腐蚀性能,制备了一种6063铝合金苯胺(BAN)封闭膜.采用极化曲线及交流阻抗技术研究了不同体积分数苯胺所制备的封闭膜的电化学性质.与去离子水中的封闭膜及基体的铝合金相比,极化曲线结果表明当苯胺的体积分数为0.12％ ～0.42％时,生成的苯胺封闭膜具有较正的点腐蚀电位及较低的腐蚀电流;交流阻抗谱数据也显示当苯胺的体积分数为0.12％～0.42％时,封闭膜具有较高的腐蚀阻抗,说明苯胺封闭膜具有较好的耐腐蚀性能.全浸失质量速率测试结果也表明苯胺封闭膜对6063铝合金有一定的防护作用.采用扫描电镜对样品的表面形貌进行了测试,测试结果与其电化学现象一致.
关键词:
材料保护
,
涂层
,
铝合金
,
苯胺
,
耐腐蚀
