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21.
基于密度泛函理论(DFT)的第一性原理计算,研究了过渡金属元素Sc、Cr和Mn掺杂对Mg2Ge晶体光、电、磁性质的影响。结果表明,Sc掺杂能使Mg2Ge的费米能级进入导带,呈n型简并半导体;Cr和Mn掺杂能使Mg2Ge能带结构和态密度在费米能级附近产生自旋劈裂而形成净磁矩,表现为半金属磁体和稀磁半导体,体系净磁矩均来自杂质原子3d轨道电子及其诱导极化的Ge4p态和Mg2p态自旋电子。与本征Mg2Ge相比,掺杂体系静态介电常数增大,扩展了吸收光谱,提升了近红外光波段吸收能力。 相似文献
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Acidichromism of indolinospirooxazines in isopropanol 总被引:1,自引:0,他引:1
1,3,3-tnmethyl-spiro[mdolino-2,3'-[2H]naphtho[2,1-b] [1,4]oxazine(SP1) and 1,3,3-trimen-thyl-9-methoxy-spiro[indolino2,3'-[2H]naphtho[2,1-b] [ 1,4]oxazine] (SP2) react with hydrochloric acid to form the complex SP HCl in isopropanol solution at room temperature The absorption maxima of these complexes are 440 and 463 nm respectively In acidic media,the opening form of spirooxazine can react with hydrochloric acid to form the complex PMC HCl via zwittenon form The absorption spectra of PMC HCl are obviously hypsochromic shifted compared with the reported spectra of the complex in neutral media In the mean time,the thermal stability of the complex is increased.The first order kinetics for the decoloration process of the acidichromic product of the opening form was determined and the lifetimes of these products are 180 and 200 s,respectively. 相似文献
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