Neutron- and x-ray-diffraction measurements of the bulk modulus of boron

Electronic structures and mechanical properties of boron and boron-rich crystals (Part I)

“…This is a general trend, which is one of the consequences of thermodynamic stability [54]. [29,30]; c [48]; d [48][49][50]; e [51]; f [51][52][53]. …”

Polycrystalline γ-boron: As hard as polycrystalline cubic boron nitride

“…Table 3 Table 2. Present our results of Young's modulus (E), bulk modulus (B), shear modulus (G), and Poisson's ratio (υ) of polycrystalline γ-and β-B, respectively, in comparison with previous experimental and calculated results [2,6,14,17,19,22,24,25,[31][32][33]. Table 3.…”

Electronic structures and mechanical properties of boron and boron-rich crystals (Part 2)

“…This gives a positive value for ∂ln α rh /∂p. On the other hand, those data of [32] and [1] seem to give negative values for ∂ln α rh /∂p. In these data, the pressure dependence of ahex and chex is so close, that it is marginal to resolve which is larger.…”

“…In these data, the pressure dependence of ahex and chex is so close, that it is marginal to resolve which is larger. Hence, we can ignore those data of [32] and [1] for the argument on Δα rh . In this way, we have seen that the way of deformation, which enhances the initial anisotropy of crystal is the way in which the relaxation is most efficient.…”

“…The equations of states have been examined for various polymorphs; for β-rhombohedral boron in ranges of 0-10 GPa [32], 0-100 GPa [1], and 0-30 GPa with elevated temperatures [2], for α-rhombohedral boron 0-100 GPa [17,33], and for boron carbide 0-11 GPa [34]. In all the cases, Murnaghan's equation-ofstate [35] …”