Magnetothermal study of the hybrid frustrated magnet Dy2-x Tbx Ti2 O7

The two pyrochlore titanates Dy2 Ti2 O7 and Tb2 Ti2 O7 have low temperature magnetic states that result from geometrical frustration of the spin-spin interactions between neighboring rare-earth ions. Dy2 Ti2 O7 is a canonical spin ice material, while the Tb moments in Tb2 Ti2 O7 have a liquidlike cooperative paramagnetic state at low temperatures. We report magnetic and thermal properties of the hybrid rare-earth titanates, Dy2-x Tbx Ti2 O7, with 0≤x≤2. We find that both the magnetic and thermal properties of the materials are strongly affected by the mixture of the ions on the sites, and that the ground state of Dy2-x Tbx Ti2 O7 is different from both spin ice and spin liquid, i.e., Dy2-x Tbx Ti2 O7 is not a simple mixture of spin ice and spin liquid components or the corresponding nonmagnetic diluted species. The strongly altered low temperature behavior is presumably associated with the Dy-Tb spin interactions and the altered crystalline electric field, suggesting that such hybrid frustrated materials offer an alternative avenue through which to explore geometrical magnetic frustration.