Theoretical calculation of positron lifetimes in CoAl and CoTi : Special issue on grain boundaries, interfaces, defects and localized quantum structures in ceramics
Theoretical calculation of positron lifetimes in CoAl and CoTi : Special issue on grain boundaries, interfaces, defects and localized quantum structures in ceramics
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CoAl 和 CoTi 中正电子寿命的理论计算：陶瓷中晶界、界面、缺陷和局域量子结构的特刊
DOI：
10.2320/matertrans.43.1451
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
Y. Shirai
中科院分区：
文献类型：
--
作者：
M. Mizuno;H. Araki;Y. Shirai
使用DV-Xa电子结构计算计算了B2结构中金属间化合物CoAl和CoTi结晶的体相和空位的正电子态，并与实验结果进行了比较。计算出的 CoAl 中的正电子寿命可以解释 CoAl 中正电子寿命的成分依赖性。计算得出的 CoTi 中 Ti 空位处的正电子寿命比 Co 空位处的正电子寿命长。从Ti到Co的电荷转移导致空位处正电子波函数的局域化差异。在被带正电的Ti原子包围的Co空位处，正电子波函数不像Ti空位处那样局域化，这降低了正电子寿命。计算结果表明，金属间化合物中的正电子寿命不能与纯组分的正电子寿命直接相关，并且组成原子之间的电荷转移影响正电子波函数的局域化。
Positron states for the bulk and vacancy in intermetallic compounds CoAl and CoTi crystallizing in the B2 structure have been calculated using the DV-Xa electronic structure calculation and compared with experimental results. The calculated positron lifetimes in CoAl can explain the compositional dependence of the positron lifetimes in CoAl. The calculated positron lifetime at the Ti vacancy in CoTi is longer than that at the Co vacancy. The charge transfer from Ti to Co leads to the difference of the localization of the positron wave function at the vacancy. At the Co vacancy site surrounded by the positively charged Ti atoms, the positron wave function does not localize as well as at the Ti vacancy site, which decrease the positron lifetime. The calculated results suggest that the positron lifetimes in intermetallic compounds can not be directly correlated to those of the pure component and the charge transfer between the constituent atoms affects the localization of the positron wave function.
影响因子：
3.7
作者：
N. Kulikov;A. Postnikov;G. Borstel;J. A. S. S. O. Physics-J.-A.-S.-S.-O.-Physics-1410184010;Troitsk;Russia.;Osnabrueck University
通讯作者：
N. Kulikov;A. Postnikov;G. Borstel;J. A. S. S. O. Physics-J.-A.-S.-S.-O.-Physics-1410184010;Troitsk;Russia.;Osnabrueck University