NEUTRON-SCATTERING STUDIES OF GEOMETRICALLY FRUSTRATED PYROCHLORE ANTIFERROMAGNETS

Elastic and inelastic neutron scattering work on the cubic pyrochlore antiferromagnets Y2Mo2O7, Tb2Ti2O7, and Tb2Mo2O7, is reviewed. These m aterials are characterized by antiferromagnetically coupled moments re siding on a network of corner-sharing tetrahedra. Geometrical frustrat ion manifests itself strongly in such systems in that two of them disp lay a spin-glass-like transition in the apparent absence of chemical d isorder, while the other remains paramagnetic to at least 0.1 K, despi te developing antiferromagnetic short-range order at 50 K. (C) 1998 El sevier Science B.V. All rights reserved.