Using a combination of static and time dependent magnetic susceptibility measurements we have examined the nonconventional spin glass phase of the 2-dimensional kagomé antiferromagnet (H3O)Fe3(SO4)2(OH)6. In contrast with 2-dimensional site-disordered spin glasses, ac susceptibility results show critical behaviour at finite temperatures. This transition agrees well with a predicted anisotropy-d...

Geometric frustration inhibits magnetic systems from ordering, opening a window to unconventional phases of matter. The paradigmatic frustrated lattice in three dimensions host spin liquid is the pyrochlore, although there remain few experimental compounds thought realize such state. Here we go beyond pyrochlore via molecular design metal-azolate framework [Mn(II)(ta)$_2$], which realizes close...

Nanocrystalline La2Sn2O7 and La2Sn1.8Co0.2O7 with a phase-pure pyrochlore structure were synthesized by a hydrothermal method, and their catalytic activity was investigated for soot combustion. The as-synthesized catalysts presented relatively larger surface area, and pore volume, which was benefit to the gas molecule diffusion in the reaction. A uniform spherical structure with particle size o...

The structural, electronic, and optical properties of pyrochlore-type Pb(2)Ir(2)O(6)O(0.55)('), which is a metal without spatial inversion symmetry at room temperature, were investigated. Structural analysis revealed that the structural distortion relevant to the breakdown of the inversion symmetry is dominated by the Pb-O' network but is very small in the Ir-O network. At the same time, gigant...

High oxygen conductivities can be achieved in cation ordered LnxZrl_=O2_l x (Ln=Gd, Nd) solid solutions with pyrochlore (P) structure. High values of the pre-exponentlal factor °o are correlated with the degree of anion disorder in the 8b oxygen sublattice (neutron diffraction). The activation energy AH is lowered by cation ordering (F-P transition; effect of x) due to the occurence of a prefer...

Correlation functions (CFs) of the classical Heisenberg antiferromagnet on the pyrochlore lattice are studied by solving exactly the infinite-component spin-vector model. As in many Fully Frustrated Lattices, the constraint due to the minimization of the energy and the particular structure based on corner sharing tetrahedra both contribute to the creation of local degrees of freedom. The result...

Submitted for the MAR08 Meeting of The American Physical Society Spin Waves and Quantum Criticality in the Frustrated XY Pyrochlore Antiferromagnet Er2Ti2O7 JACOB RUFF, PATRICK CLANCY, BRUCE GAULIN, HANNA DABKOWSKA, MEHMET RAMAZANOGLU, McMaster University, JASON GARDNER, NCNR, ALEX BOURQUE, MARY ANNE WHITE, Dalhousie University, YIMING QIU, JOHN COPLEY, NCNR — We report recent single crystal ne...