Rattling-Induced Superconductiviy in the β-Pyrochlore Oxides AOs2O6

Magnetic pyrochlore oxides

Within the past 20 years or so, there has occurred an explosion of interest in the magnetic behavior of pyrochlore oxides of the type A 2 B 4+ 2 O7 where A is a rare-earth ion and B is usually a transition metal. Both the A and B sites form a network of corner-sharing tetrahedra which is the quintessential framework for a geometrically frustrated magnet. In these systems the natural tendency to...

Monte Carlo Study of the Pyrochlore Double-Exchange Model –Frustration Effects in Molybdenum Pyrochlore Oxides–

where t is the transfer integral for nearest-neighbor sites hiji on the pyrochlore lattice, JH represents the Hund’s-rule coupling between the itinerant electron spin ~si and the localized spin ~ Si, while JAF is the super-exchange antiferromagnetic interaction between the neighboring localized spins. The first two terms induce the double-exchange ferromagnetic interactions through the kinetic ...

Effects of Rattling Phonons on the Dynamics of Quasiparticle Excitation in the -Pyrochlore KOs2O6 Superconductor

Novel rattling of K atoms in aluminium-doped defect pyrochlore tungstate.

Rattling dynamics have been identified as fundamental to superconductivity in defect pyrochlore osmates and aluminium vanadium intermetallics, as well as low thermal conductivity in clathrates and filled skutterudites. Combining inelastic neutron scattering (INS) measurements and ab initio molecular dynamics (MD) simulations, we use a new approach to investigate rattling in the Al-doped defect ...

Abstract No. Barn0393 Pressure-Induced Cation Migration and Volume Expansion in Defect Pyrochlore Oxides

No. Barn0393 Pressure-Induced Cation Migration and Volume Expansion in Defect Pyrochlore Oxides P. W. Barnes (Ohio State Univ., Chemistry), P. M. Woodward (Ohio State Univ., Chemistry), Y. Lee (BNL, Physics), T. Vogt (BNL, Physics), J. A. Hriljac (Univ. Birmingham, Chemical Sciences) Beamline(s): X7A Introduction: Microporous materials, such as zeolites [1,2], undergo pressure-induced volume ex...