Spin-glass-like behavior in Y2Mo2O7, a concentrated, crystalline system with negligible apparent disorder

The pyrochlore-structure material Y2Mo2O7 is apparently a well-ordered crystalline compound with a concentrated magnetic, Mo4+, sublattice. Yet, the magnetic properties are typical of spin glasses. There is a maximum in the zero-field cooled susceptibility at 22K, no long range magnetic order at 4.2 K, sample-history dependent behavior below 22 K and Curie-Weiss law deviations below 80 K. The effective magnetic moment is 2.06 μBMo4+ and θc = −61 K . The spin-glass-like properties are attributed to a frustrated Mo4+ sublattice with competing ferromagnetic and antiferromagnetic interactions.