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用第一性原理研究放射性同位素铀在针铁矿(α-FeOOH)中的占位情况,分别考虑铀原子替代针铁矿中的铁的替位缺陷和铀的多种八面体和多种四面体间隙缺陷.计算发现了三个最稳定的缺陷构型,它们分别对应于一个铀替位缺陷(S)及其中的一个铀的八面体(O)和四面体(T)间隙缺陷,其形成能分别为-13.49,-3.86,-1.60eV.也研究了两个相邻的铀原子在针铁矿中的占位情况,发现双铀原子很容易掺入到相邻的SS或OS位,它们的形成能分别为-27.392和-16.214eV,结合能分别为-0.417和-1.131eV.表明双原子铀在针铁矿中会以SS形式发生偏聚而较难以OS形式偏聚.
The first principle is used to study the occupancy of radioactive isotope uranium in goethite (α-FeOOH), the substitution of uranium atoms for iron substitution in goethite and the uranium octahedral and tetrahedral Gap Defects Calculated Find the three most stable defect configurations that correspond to a uranium replacement defect (S) and one of the uranium octahedral (O) and tetrahedron (T) interstitial defects, respectively, that form Which can be -13.49, -3.86 and -1.60eV, respectively.At the same time, the occupation of two adjacent uranium atoms in goethite was also investigated and it was found that uranium atoms could be easily incorporated into adjacent SS or OS sites, Their formation can be -27.392 and -16.214eV, respectively, and the binding energies are -0.417 and -1.131eV, respectively. It shows that the diatomic uranium segregates in the form of SS in goethite and is more difficult to segregate in the OS form.