【摘要】 铀氮化物因其独特的物理化学性质及优良的性能而成为核燃料循环系统中重要的燃料材料,是核领域的研究热点材料之一。此外,铀氮化物也被用作抗腐蚀涂层材料,在金属铀的表面腐蚀防护领域具有重要的应用价值。在铀-氮体系中,五种结构铀氮化物,包括NaCl型UN、HgIn型UN、Mn₂O₃型α-U₂N₃、La₂O₃型β-U₂N₃和CaF₂型UN₂,已经被确认并进行了广泛研究。但是到目前为止,由于铀氮化物复杂的非化学计量比问题,导致对上述物相之间的转化关系的认识仍不清楚;而不同化学计量比的铀氮化物由于其电子结构的差异,使得其基本物理化学性质发生了根本的变化。有关铀氮化物晶体结构和电子结构方面的研究是探讨其优异性能起因的第一步,因此引起研究者的广泛关注。本文在归纳和分析大量文献的基础上,结合本课题组在铀氮化物相关方面的研究成果,着重介绍铀氮化物晶体结构和电子结构方面的主要进展,并对铀氮化物相结构的转化规律以及电子结构的演化规律进行总结,以期为铀氮化物的实验研究和功能应用提供参考。更多还原

【Abstract】 Uranium nitrides have aroused more and more attention due to their unique physical and chemical properties and their excellent performance in applications such as nuclear fuel and anti-corrosion coating for uranium metal. In U-N system,five structures of uranium nitrides,including NaCl-type UN,HgIn-type UN,Mn₂O₃-type α-U₂N₃,La₂O₃-type β-U₂N₃ and CaF₂-type UN₂,have been identified and studied extensively. Up to now,because of the complex nonstoichiometric problems of uranium nitrides,the understanding of the transformation relationship betw een these phases is still ambiguous. In addition,the basic physical properties of uranium nitrides have been fundamentally changed due to the difference in electronic structures of uranium nitrides w ith different nitrogen content. The studies of the crystal structure and electronic structure of uranium nitrides are the first step in exploring the causes of their excellent performances,and have attracted much attention in recent years. Based on the analysis and summary of the literatures,as w ell as the research results of our group,this paper review s the main progress in the study of the crystal structure and electronic structure of uranium nitrides. The phase transformation and electronic structure evolutions of uranium nitrides are summarized,w hich is expected to provide reference for the experimental studies and functional applications of uranium nitrides.更多还原