Two-Stage Growth Mechanism for Synthesizing Pyrochlore Iridate Thin Films*

To harness the unique topological and magnetic characteristics of pyrochlore iridates, we introduce a new two-stage growth strategy to fabricate stoichiometric and epitaxial thin films. The first synthesis stage focuses on achieving an amorphous continuous network, subsequently transitioning to the critical solid phase epitaxy (SPE) stage. In the solid epitaxy (SPE) stage, we employ an in-situ post-annealing method in a pure oxygen environment to ensure the preservation of stoichiometry and structural uniformity across the film's depth. A distinguishing feature of this SPE stage is the use of directional planar laser-heat annealing, drastically enhancing the transformation kinetics from the glassy to the crystalline phase. Also, this work draws interesting parallels with other pyrochlore iridates and titanates fabrication techniques, setting a new approach for the synthesis of epitaxial films of pyrochlores with the platinum group metals