Structural, optical and magnetic properties of a dilute magnetic semiconductor based on Ga-doped ZnO and Co.

A wide bandgap oxide/transition metal multilayered structure, consisting of four submicron-thick Ga-doped ZnO layers and three ultrathin Co metal layers, is studied to highlight the induction of room temperature ferromagnetism (RTFM), a fundamental outcome of investigations dealing with dilute magnetic semiconductors and multiferroic materials. A comprehensive study including the structural, optical and magnetic properties of both as-deposited and high-temperature annealed samples is described. Optical transmittance spectroscopy and x-ray diffraction measurements confirm the conversion of the layered structure into a solid-state solution of Co within the Ga-doped ZnO after annealing. The study discloses RTFM in the as-deposited state due to nonoxidized metal components within the multilayer structure. [ABSTRACT FROM AUTHOR]