Worm-graphene: A two-dimensional orthorhombic carbon semimetal with massless Dirac fermion

Two-dimensional carbon materials with an anisotropic Dirac cone: high stability and tunable Fermi velocity

“…[1][2][3] Since then, many 2D carbon allotropes have been theoretically predicted with rich electronic properties, e.g., superconductors, [4][5][6][7] metals, 8,9 semiconductors, [10][11][12] and semimetals. [13][14][15] Among all the 2D allotropes, Dirac-cone materials have attracted much attention due to their extraordinary electrical properties. Using first-principles methods, many Dirac 2D carbon allotropes have been proposed, such as a-graphdiyne, a-2 graphyne, S-, D-, and E-graphene, and phagraphene.…”

Anisotropic structural, vibrational, electronic, optical, and elastic properties of single-layer hafnium pentatelluride: an ab initio study

“…Elastic constants characterize the ability of a material to deform under small stresses and then returning to its original shape after application of the stress ceases. For an orthorhombic structure, the Born–Huang criteria 63 of mechanical stability in terms of the elastic strain tensor constants, C 11 , C 33 , C 13 , and C 66 , read as: 64 C 66 > 0 C 11 C 33 − C 13 2 > 0 As listed in Table 3, the calculated C ij values satisfy the Born–Huang criteria, indicating the mechanical stability of orthorhombic single-layer HfTe 5 . The linear-elastic properties of the mechanically stable HfTe 5 layer can be represented by two independent constants, namely the in-plane stiffness ( C ) and the Poisson ratio ( υ ).…”

“…Elastic constants characterize the ability of a material to deform under small stresses and then returning to its original shape after application of the stress ceases. For an orthorhombic structure, the Born-Huang criteria 63 of mechanical stability in terms of the elastic strain tensor constants, C 11 , C 33 , C 13 , and C 66 , read as: 64 C 66 > 0…”

Prediction of single-layer antimony oxyselenide (Sb2O2Se2): metal-to-semiconductor transition via hydrogenation

“…Elastic properties of single-layer Sb 2 O 2 Se 2 H 2 are investigated by means of its linear-elastic tensor elements, C ij . Firstly, the mechanical stability of the predicted single-layer is examined using Born-Huang criteria for cubic crystal in 2D [48] as defined in equation ( 2). The three non-zero linear-elastic parameters, namely C 11 , C 12 and C 44 , are calculated to be 57, 11, and 15 N m −1 , respectively.…”