High-pressure solid-state synthesis advances boost discoveries of new materials and unusual phenomena but endures stringent recipe conditions, poor yield, and high cost. A methodological approach for accelerated and precisely high-pressure synthesis is therefore highly desired. Here, we take the exotic double-perovskite-related nonmagnetic Li2 B +4 B′+6O6 as an example to show the pipeline of data-mining, high-throughput calculations, experimental realization, and chemical interception of metastable phases. A total of 140 compounds in 7 polymorph categories were initially screened by the convex hull, which left ∼50% candidates in chemical space on the phase diagram of pressure-dependent polymorph evolution. Li2TiWO6 and Li2TiTeO6 were singled out for experimental testing according to the predicted map of crystal structure, function, and synthesis parameters. Computation on surface energy effect and interfacial chemical strain suggested that the as-made high-pressure R3-Li2TiTeO6 polymorph cannot be intercepted below a critical nanoscale but can be stabilized in heterojunction film on a selected compressive substrate at ambient pressure. The developed methodology is expected to accelerate the big-data-driven discovery of generic chemical formula-based new materials beyond perovskites by high-pressure synthesis and shed light on the large-scale stabilization of metastable phases under mild conditions.

High-pressure heaters in large volume presses must reconcile potentially contradictory properties, and the whole highpressure and high-temperature (HPHT) community has been engaged for years to seek a better heater. LaCrO 3 (LCO)-based ceramic heaters have been widely applied in multianvil apparatus; however, their performance is far from satisfactory, motivating further research on the chemical optimization strategy and corresponding thermochemical mechanism. Here, we adopted a chemical-screening strategy and manufactured tubular heaters using the electrically, chemically, and mechanically optimized Sr− Cu codoped La 0.9 Sr 0.1 Cr 0.8 Cu 0.2 O 3−δ (LSCCuO-9182). HPHT examinations of cylindrical LSCCuO-9182 heaters on Walker-type multianvil apparatuses demonstrated a small temperature gradient, robust thermochemical stability, and excellent compatibility with high-pressure assemblies below 2273 K and 10 GPa. Thermochemical mechanism analysis revealed that the temperature limitation of the LSCCuO-9182 heater was related to the autoredox process of the Cu dopant and Cr and the exchanging ionic migration of Cu and Mg between the LSCCuO-9182 heater and the MgO sleeve. Our combinatorial strategy coupled with thermochemical mechanism analysis makes the prioritization of contradictory objectives more rational, yields reliable LCO heaters, and sheds light on further improvement of the temperature limitation and thermochemical stability.

No abstract