| Praseodymium-filled skutterudites RT4X12 are body centered cubic (bcc) structures that belong to the space group Im3¯ (no.204) where R stands for rare earth elements (Pr, Ce, La, U, etc.), T stands for transition metal ions (Fe, Ru, Os) and X represents pnictogens (P, As, Sb). Three different praseodymium-filled skutterudites are considered in the present study: PrFe4P12, PrOs4Sb 12 and PrRu4P12. These materials were explored for their crystal structure and interesting properties. Calculations are made of the following: (i) the electric quadrupole moment possessed by the Pr 4f2 ground state doublet, (ii) the electric quadrupole moment produced by unique displacements of transition metal ions, creating a cubic to tetragonal type of distortion in the crystal, and (iii) long-range quadrupole interactions between the Pr 4f2 electrons and the transition metal ions. The present work is limited to the long-range quadrupole interactions between the Pr 4f2 electrons and the transition metal ions. Further studies focusing on long- and short-range electric quadrupole interactions among the conduction electrons, the Pr 4f2 electrons and the transition metal ions would be essential in order to more fully develop the desired theory. (Abstract shortened by UMI.)... |
