Epitaxial Stabilization of Metastable 3C BaRuO3 Thin Film with Ferromagnetic Non‐Fermi Liquid Phase

Abstract

AbstractThin films of perovskite ruthenates of the general formula ARuO3 (A = Ca and Sr) are versatile electrical conductors for viable oxide electronics. They are also scientifically intriguing, as they exhibit nontrivial electromagnetic ground states depending on the A‐site element. Among them, realization of the cubic perovskite (3C) BaRuO3 in thin film form has been a challenge so far, because the 3C phase is metastable with the largest formation energy among the various polymorph phases of BaRuO3. In this study, 3C BaRuO3 thin films are successfully prepared employing epitaxial stabilization. The 3C BaRuO3 thin films show itinerant ferromagnetism with a transition temperature of ≈48 K and a non‐Fermi liquid phase. The epitaxial stabilization of the 3C BaRuO3 further enables to make a standard comparison of perovskite ruthenates, thereby establishing the importance of the RuO orbital hybridization in understanding the itinerant magnetic system.