High-Pressure Routes to New Pyrochlores and Novel Magnetism

The pyrochlore structure (A 2B 2O 7) has been an object of consistent study by materials scientists largely due to the stability of the cubic lattice with respect to a wide variety of chemical species on the A or B sites. The criterion for stability under ambient conditions is controlled by the ratio of these cations, which is empirically 1.36 < R A/R B < 1.71. However, under applied pressure synthesis conditions, the pyrochlore lattice is stable up to R A/R B ～ 2.30, opening up possibilities for new compounds. In this review, we will highlight recent work in exploring new rare-earth pyrochlores such as the germanates RE 2Ge 2O 7 and platinates RE 2Pt 2O 7. We highlight recent discoveries made in these pyrochlores such as highly correlated spin ice behavior, spin liquid ground states, and exotic magnetic ordering. View Full-Tex