Here, we present experimental and computational evidences to support that rocksalt cubic VO is a strongly correlated metal with non-Fermi-liquid thermodynamics and an unusually strong spin-lattice coupling. An unexpected change of sign of metallic thermopower with composition is tentatively ascribed to the presence of a pseudogap in the density of states. These properties are discussed as signatures of the proximity to a magnetic quantum phase transition. The results are summarized in an electronic phase diagram for the $3d$ monoxides, which resembles that of other strongly correlated systems. The structural and electronic simplicity of $3d$ monoxides makes them ideal candidates to progress in the understanding of highly correlated electron systems.

• Received 9 May 2007

DOI:https://doi.org/10.1103/PhysRevB.76.205110