Magneto-Synthesis of Metastable Metallic States in a Spin-Orbit-Coupled Trimer Iridate

Applying modest magnetic fields—fractions of a tesla—during high-temperature crystal growth can substantially modify the structural and electronic ground state of spin–orbit–coupled, antiferromagnetic trimer lattices. In an iridate model system, this magneto-synthesis approach [1] stabilizes a structurally compressed, metastable metallic phase that is inaccessible through conventional synthesis methods. The field-induced phase exhibits shortened Ir–Ir bond distances, reduced lattice distortion, and suppressed magnetic order, resulting in a pronounced insulator-to-metal transition. Electrical resistivity decreases by up to four orders of magnitude, and low-temperature specific heat measurements reveal a large enhancement of the Sommerfeld coefficient, indicative of a strongly correlated metallic state. First-principles calculations show that the field-stabilized phase lies significantly above the equilibrium ground state in energy, confirming its metastable nature. These findings establish magneto-synthesis as a versatile route for accessing non-equilibrium quantum phases in strongly correlated materials [2].