Structural, electronic and mechanical properties of W1−xTcxB2 alloys

A detailed theoretical study of the structural, elastic and electronic properties of W1−xTcxB2 (x=0.1∼0.9) alloys is carried out by using the plane-wave pseudopotential approach to the density-functional theory within the generalized gradient approximation (GGA). The most stable structure is found as W0.9Tc0.1B2 due to the lowest formation energy value and Band filling theory. Furthermore, the band structural and density of states (DOS) are computed for each composition x (0.1∼0.9). The elastic constants of W1−xTcxB2 for all x composition are obtained, then the secondary results such as bulk modulus, shear modulus, Youngʹs modulus, Poissonʹs ratio, and hardness of polycrystalline aggregates are derived, and the relevant mechanical properties are also discussed. Moreover, we have predicted that W0.9Tc0.1B2 alloy is potential superhard material.