Role of geometrical frustration in metallic metastability

Determine whether geometrical frustration is essential for the formation and persistence of a metastable metallic phase in metal–insulator-transition systems.

Background

Metastable metallic phases have previously been discussed in triangular-lattice materials such as θ-(BEDT-TTF)2X and 1T-TaS2 in connection with competing charge-ordering patterns generated by geometrical frustration. The paper investigates tungsten-substituted VO2, a non-triangular system, and demonstrates that elemental substitution can produce a thermally quenched metastable metallic phase there. Nevertheless, the authors explicitly leave unresolved whether geometrical frustration is fundamentally necessary for metallic metastability or merely one of several mechanisms capable of producing it.