Structure and Electronic Properties of the Orthorhombic MoRuP Superconductor Prepared at High Pressure

Published

April 1, 2003

Author(s)

Winnie K. Wong-Ng, W Y. Ching, Y N. Xu, James A. Kaduk, I Shirontani, L Swartzendruber

Abstract

The new superconductor, orthorhombic MoRuP (o-MoRuP), was prepared under high pressure, and its structure was refined using the X-ray Rietveld technique. The grayish-black sample of o-MoRuP is a superconductor with T_c=15.5K and having space group Pnma and lattice parameters a = 6.03503(16) , b = 3.85311(8) , and c = 6.94355(17) . The structure of o-MoRuP is characterized by layers (parallel to the ac plane) of Mo, Ru and P atoms. Based on the accurately determined crystal structure, the band structure and the density of states (DOS) of o-MoRuP were calculated by a first-principles density functional method and compared with those of the isostructural superconductor o-ZrRuP (T_c=4K). It is shown that the high T_c in o-MoRuP is directly related to the higher level of the DOS at the Fermi level (EF) and is traced to be predominately from the Mo-4d orbitals. The calculated values of the DOS at EF are 0.46 and 0.33 states/eV-atom for the Mo- and Zr-analogs, respectively. The electronic bonding in these two crystals is analyzed in terms of the Mulliken effective charge and the bond order values. The bonding in o-MoRuP differs from that in o-ZrRuP in that there is a short (2.44 ) Mo-P bond. The X-ray reference pattern of o-MoRuP prepared using a Rietveld decomposition technique has been submitted to the International Center for Diffraction Data (ICDD) to be included in the Powder Diffraction File (PDF).

Citation

Physical Review B (Condensed Matter and Materials Physics)

Volume

67

Issue

No. 14

Pub Type

Journals

Keywords

electronic properties, first-principles density functional meth, MoRuP, orthorhombic phase, structure, superconductor, x-ray diffraction pattern

Citation

Wong-Ng, W. , Ching, W. , Xu, Y. , A., J. , Shirontani, I. and Swartzendruber, L. (2003), Structure and Electronic Properties of the Orthorhombic MoRuP Superconductor Prepared at High Pressure, Physical Review B (Condensed Matter and Materials Physics) (Accessed April 26, 2024)