Ideal Strengths and Bonding Properties of PuO2 under Tension
Ideal Strengths and Bonding Properties of PuO2 under Tension
复制标题
PuO2 在张力下的理想强度和粘合性能
DOI：
10.1088/0256-307x/28/4/047101
复制
发表时间：
2011
影响因子：
3.5
通讯作者：
Zhang Ping
中科院分区：
文献类型：
--
作者：
Wang Bao-Tian;Zhang Ping
我们基于密度泛函理论在局域密度近似（LDA）+U形式下对PuO 2进行了第一性原理计算拉伸测试，以研究其在四个代表性方向上的结构，机械，磁性和内在成键性质：[001]，[100]，[110]和[111]。应力-应变关系表明，当应变为0.36、0.36、0.22和0.18时，四个方向的理想抗拉强度分别为81.2、80.5、28.3和16.8GPa。[001]和[100]方向明显强于其他两个方向，因为更多的Pu-O键参与了拉伸过程。通过沿着[001]方向的电荷和态密度分析，我们发现Pu-O键的强离子/共价混合键特征被拉伸应变削弱，当拉伸应力超过约79 GPa时，PuO 2将表现出绝缘体到金属的转变。
We perform a first-principles computational tensile test on PuO2 based on density-functional theory within a local density approximation (LDA)+U formalism to investigate its structural, mechanical, magnetic and intrinsic bonding properties in four representative directions: [001], [100], [110] and [111]. The stress-strain relations show that the ideal tensile strengths in the four directions are 81.2, 80.5, 28.3 and 16.8 GPa at strains of 0.36, 0.36, 0.22 and 0.18, respectively. The [001] and [100] directions are prominently stronger than the other two directions since more Pu—O bonds participate in the pulling process. By charge and density of state analysis along the [001] direction, we find that the strong mixed ionic/covalent character of the Pu—O bond is weakened by tensile strain and PuO2 will exhibit an insulator-to-metal transition after tensile stresses exceeding about 79 GPa.