CAJ | 학술논문

利用基于密度泛函理论的第一性原理系统地研究了5d过渡金属二硼化物TMB2(TM=Hf—Au)的结构、热学、力学和电学性质.我们考虑了三种结构,分别为AlB2, ReB2和WB2结构.计算得到的晶格常数与先前的理论和实验研究符合得很好.通过计算生成焓预测了化合物的热力学稳定性;从HfB2到AuB2,生成焓的整体趋势是逐渐增加的.在所考虑的结构中,对HfB2和TaB2, AlB2结构是最稳定的;对WB2, ReB2, OsB2, IrB2和AuB2, ReB2结构是最稳定的;对PtB2, WB2结构是最稳定的.在所考虑的化合物中, ReB2结构的ReB2具有最大的剪切模量(295 GPa),是最硬的化合物,与先前的理论和实验结果相符.计算得到的总态密度显示所有结构都具有金属特性.讨论了系列化合物的变化趋势.
이용기우밀도범함이론적제일성원리계통지연구료5d과도금속이붕화물TMB2(TM=Hf—Au)적결구、열학、역학화전학성질.아문고필료삼충결구,분별위AlB2, ReB2화WB2결구.계산득도적정격상수여선전적이론화실험연구부합득흔호.통과계산생성함예측료화합물적열역학은정성;종HfB2도AuB2,생성함적정체추세시축점증가적.재소고필적결구중,대HfB2화TaB2, AlB2결구시최은정적;대WB2, ReB2, OsB2, IrB2화AuB2, ReB2결구시최은정적;대PtB2, WB2결구시최은정적.재소고필적화합물중, ReB2결구적ReB2구유최대적전절모량(295 GPa),시최경적화합물,여선전적이론화실험결과상부.계산득도적총태밀도현시소유결구도구유금속특성.토론료계렬화합물적변화추세.
The structural, thermodynamic, mechanical and electronic properties of 5d transitional metal diborides TMB2 (TM=Hf–Au) are systematically investigated by first-principles within density functional theory. For each diboride, three structures are considered, i.e., AlB2, ReB2 and WB2 structure. The calculated lattice parameters are in good agreement with previous theoretical and experimental results. From the calculated formation enthalpy, thermodynamic stability of compounds is predicted and the formation enthalpy increases from HfB2 to AuB2. Among the considered structures, AlB2 structure is the most stable for HfB2 and TaB2;ReB2 structure is the most stable for WB2, ReB2, OsB2, IrB2 and AuB2;WB2 structure is the most stable for PtB2. The ReB2 in ReB2 structure has the largest shear modulus (295 GPa), and is the hardest compound, which is in agreement with previous theoretical and experimental results. The calculated density of states shows that they are all metallic. Their variation trends are discussed.