Universal geometric frustration in pyrochlores.

ABSTRACT: Materials with the pyrochlore/fluorite structure have diverse technological applications, from magnetism to nuclear waste disposal. Here we report the observation of structural instability present in the pyrochlores A₂Zr₂O₆O' (A = Pr, La) and Yb₂Ti₂O₆O', that exists despite ideal stoichiometry, ideal cation-ordering, the absence of lone pair effects, and a lack of magnetic order. Though these materials appear to have good long-range order, local structure probes find displacements, of the order of 0.01 nm, within the pyrochlore framework. The pattern of displacements of the A₂O' sublattice mimics the entropically-driven fluxional motions characteristic of and well-known in the silica mineral β-cristobalite. The un

SUBMITTER: Trump BA 

PROVIDER: S-EPMC6033937 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature