Vanadium-induced decrease in the magnetization of a VxCo1−x alloy film on the W(110) surface

The magnetic and structural properties of a series of VxCo1−x alloy films prepared in a variety of compositions on a W(110) surface were investigated using spin-resolved photoemission spectroscopy (SRPES) and low-energy electron diffraction (LEED) measurements. The epitaxial structures of the films were preserved over all V concentrations, despite the observation of a structural phase transition (SPT: hcp/bcc at x = 0.38), which was apparent from the LEED images. A magnetic phase transition (MPT) from ferromagnetic to paramagnetic occurred in the Co-rich region at x = 0.38. The SPT (from hcp and bcc) and MPT (from ferromagnetic to paramagnetic) were clearly correlated at x = 0.38, possibly due to changes in the electronic and magnetic structures of the valence band, as monitored by SRPES and LEED. The magnetization in the VxCo1−x alloy films on a W(110) surface varied systematically with the V concentration, and correlations between the structural changes and magnetic properties were revealed using SRPES and LEED.

► We have investigated the epitaxial VxCo1−x alloy films grown on a W(110) surface. ► At V concentration of 38%, the films undergo the hcp-to-bcc structural transition. ► This transition is accompanied by a profound modification of the valence states. ► Magnetic phase transition and structural phase transition are closely correlated.