单轴大应变下二维六角氮化硼的结构变化  

Structure transition of two-dimensional hexagonal BN under large uniaxial strain

作　　者：李金[1] 桂贵[1] 孙立忠[1] 钟建新[1] 

机构地区：[1]湘潭大学物理系,量子工程与微纳能源技术湖南省高校重点实验室,湘潭411105

出　　处：《物理学报》2010年第12期8820-8828,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10774127;10874143);高等学校博士学科点专项科研基金(批准号:200805300003;20070530008);教育部科技创新工程重大项目培育基金(批准号:708068);湖南省研究生创新基金(批准号:CX2009B123)资助的课题~~

摘　　要：采用第一性原理方法研究了二维六角氮化硼(2Dh-BN)在单轴大应变下的结构变化.计算过程中以原胞在垂直和平行于B—N键方向的长度Lx和Ly来描述2Dh-BN所受到的应变.结果表明:在垂直于B—N键的方向施加大应变,当Lx≤0.3388nm时,体系处于简单斜方结构;随着应变的增大,体系逐渐从简单斜方结构向简单长方结构转变,当Lx≥0.3488nm时,体系处于简单长方结构,该结构是由交错并排的BN链相互作用形成;随着应变继续增大,简单长方结构中链之间的作用逐渐减小,当Lx>0.6nm最终趋向于孤立的BN链.在平行于B—N键的方向施加大应变,体系从最初的简单斜方结构直接转变成交错并排的BN链结构,没有出现长方结构,当Ly>0.571nm时,体系最终也趋向于孤立的BN链结构.Using the first-principles method,we have studied the structure transition of two-dimensional hexagonal boron nitride（2D h-BN） under large uniaxial strain.The strain is applied by changing the values of Lx and Ly,which correspond to the lengths of primitive cell in the directions perpendicular and parallel to B—N bonds,respectively.For the large asymmetrical tensile strain perpendicular to B—N bonds,the rhombic structure is stable when Lx ≤0.3388 nm.As the strain increases,the system transforms from the rhombic structure to a rectangular structure consisting of interlaced interacting BN chains,which becomes stable when Lx≥0.3488 nm.When the strain further increases,the system finally changes into the one comprised of isolated BN chains.For the 2D h-BN with large asymmetrical tensile strain distribution parallel to B—N bonds,there is no stable rectangular structure and the system becomes the one composed of isolated BN chains when Ly〉 0.571 nm.

关 键 词：二维六角氮化硼 单轴应变 电子结构 第一性原理方法 

分 类 号：TQ164[化学工程—高温制品工业]