Surfactant assisted synthesis of Co and Li doped ZnO nanocrystalline samples showing room temperature ferromagnetism

TL;DR

This paper presents a surfactant-assisted synthesis method for Co and Li doped ZnO nanocrystals that exhibit intrinsic room temperature ferromagnetism, emphasizing defect roles and reproducibility.

Contribution

It introduces a simple synthesis route for doped ZnO nanocrystals with intrinsic ferromagnetism, clarifying defect roles and enabling extension to other transition metals.

Findings

Room temperature ferromagnetism is intrinsic to the doped ZnO samples.

Defects are crucial in activating ferromagnetism in these oxides.

The synthesis method is scalable and adaptable to other transition metal dopants.

Abstract

We have developed a simple, surfactant assisted synthesis route for the preparation, in gram quantities, of Co and Li doped ZnO nanocrystalline samples showing robust room temperature ferromagnetism. Our studies show that RTF is intrinsic to Zn0.85Co0.05Li0.10O and not due to any segregated secondary phases. In addition, it has been shown that the defects play an important role in activating RTF in these oxide systems. This also provide an explanation for the widely varying results observed in the literature. The method can also be extended for the synthesis of other transition metal doped ZnO.