Abstract Chromium ion (Cr3+) doped YAlO3 host crystal shows strong prospects for the exploitation of new optical materials. However, the microstructure of Cr3+ doped of YAlO3 is still unclear. In this work, we systematically explore the structural evolutions of Cr3+ doped of YAlO3 system by using the CALYPSO method and density functional theory. A novel cage-like structure with P-1 space group is identified for the first time. The impurity Cr3+ ion can naturally substitute the Al3+ ion of the central site in the crystal lattice. The result show that the impurity Cr3+ concentration is determined to be 6.25%, which is almost comparable to the experiments. The perfect agreement between our simulated X-ray diffraction patterns and the measured ones demonstrates the validity of the ground-state structure. The calculation of electronic band structure for Cr3+ doped YAlO3 reveals a closure of the insulator band gap, forming an energy gap of 2.94 eV. The result of electronic density of states shows that it is the impurity Cr3+ ion that leads to a transition from insulator to semiconductor. By analyzing the electron localization function of Cr3+ doped of YAlO3 crystal, we conclude that the Cr–O interaction is dominantly ionic bond. The obtained results could provide an important understanding of the transition-metal doped host materials.

中文翻译：

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Cr3+掺杂原铝酸钇微观结构和电子性能的第一性原理研究

摘要 铬离子(Cr3+)掺杂的YAlO3主晶具有开发新型光学材料的广阔前景。然而，掺入 YAlO3 的 Cr3+ 的微观结构仍不清楚。在这项工作中，我们利用 CALYPSO 方法和密度泛函理论系统地探索了 YAlO3 系统中 Cr3+ 掺杂的结构演变。首次发现了具有 P-1 空间群的新型笼状结构。杂质 Cr3+ 离子可以自然地替代晶格中心位的 Al3+ 离子。结果表明，确定的杂质Cr3+浓度为6.25%，与实验几乎相当。我们模拟的 X 射线衍射图与实测图之间的完美一致性证明了基态结构的有效性。Cr3+ 掺杂 YAlO3 的电子能带结构计算揭示了绝缘体带隙的闭合，形成了 2.94 eV 的能隙。电子态密度的结果表明，是杂质 Cr3+ 离子导致了从绝缘体到半导体的跃迁。通过分析掺杂 YAlO3 晶体的 Cr3+ 的电子定域函数，我们得出结论，Cr-O 相互作用主要是离子键。获得的结果可以提供对过渡金属掺杂主体材料的重要理解。我们得出结论，Cr-O 相互作用主要是离子键。获得的结果可以提供对过渡金属掺杂主体材料的重要理解。我们得出结论，Cr-O 相互作用主要是离子键。获得的结果可以提供对过渡金属掺杂主体材料的重要理解。