Electronic structure and phase-stability studies on superconducting YNi2B2C, YRh3B, and nonsuperconducting YNi4B

The band structure and the density of states (DOS) of YNi2B2C, YRh3B, and YNi4B are obtained using the tight-binding linear muffin-tin orbital method. From our studies, we have found that the Fermi level falls on one of the peaks in the DOS curves of both YNi2B2C and YRh3B and this is responsible for superconductivity in these compounds. In order to comprehend the phase stability of these superconducting materials, the total-energy curves are drawn. The angular momentum and site decomposed DOS studies on paramagnetic YNi4B clearly show that the nickel d states are partially filled. The equilibrium lattice constants, cohesive energy, heat of formation, density of states at the Fermi level, Pauli paramagnetic susceptibility, electronic specific-heat coefficient, the electron-phonon coupling constant, and the bulk modulus and its pressure derivative are tabulated and compared with the available experimental values