Self-assembly and plasmon-enhanced ultrafast magnetization of Ag–Co hybrid nanoparticles

Abstract

Ultrafast demagnetization in magnetic nanoparticles has attracted considerable attention because of its potential applications such as spintronics. For such applications, it is important to develop materials in which ultrafast magnetization can be controlled by lower-power laser pulses. We developed a new method for fabricating Ag–Co hybrid nanoparticles in a TiO2 film using pulsed laser deposition, and elucidated ultrafast magnetization dynamics of these films by employing the pump–probe time-resolved Faraday rotation measurement. The measurements showed that localized surface plasmon resonance of the nanoparticles resulted in an enhancement of the ultrafast demagnetization of the films.