Rapid microwave-assisted synthesis of mixed B-site pyrochlores: stabilization and discovery of Ln₂InSbO₇ family

In the field of condensed matter physics, the pyrochlore oxides are one of the most intensely studied classes of materials. The combination of a magnetic rare-earth ion within a frustrated tetrahedral motif imparts a wide variety of exotic emergent phenomena, ranging from candidate quantum spin-liquids to spin-glasses to moment fragmentation. Here we present the synthesis of the entire family of mixed B-site pyrochlores Ln₂InSbO₇ (Ln: La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) using rapid microwave-assisted synthesis. Our methods produce phase pure, crystalline powders in short (<10 min. heating) time scales. Additionally, our methods enable the stabilization of the mixed B-site pyrochlores from Tb-Lu, which are classically outside of the stability-field for typical pyrochlore oxides. Magnetic characterization on the entire class of compounds draws striking parallels to the stannite analogs, suggesting several of the compounds are prime candidates for future avenues of investigation.