A Review of Magnetoelectric Composites Based on ZnO Nanostructures

Abstract

The recent advancements in magnetoelectric (ME) materials have enabled the development of functional magnetoelectric composites for sensor applications in the medical and engineering sectors, as well as in energy harvesting and material exploration. Magnetoelectric composites rely on the interaction between piezoelectric and magnetoelastic materials by coupling the magnetization-induced strain to the strain-generated potential of the piezoelectric phase. This creates an increased interest around the development of novel piezoelectric materials that not only possess favorable piezoelectric properties but also fulfill specific material criteria such as biocompatibility, bioactivity, ease of fabrication and low cost. ZnO, and its nanostructures, is one such material that has been employed in the magnetoelectric research due to its remarkable piezoelectric, semiconducting and optical properties. Thus, this article provides a comprehensive review of the available literature on magnetoelectric composites based on ZnO micro- and nanostructures, aiming to present a concise reference on the methods, applications and future prospects of ZnO-based ME composites. Specifically, a brief introduction is provided, presenting the current research interests around magnetoelectric composites, followed by a concise mention of the magnetoelectric effect and its key aspects. This is followed by separate sections describing the relevant research on ZnO magnetoelectric composites based on ZnO thin-films, either pure or doped, and nano- and microrods composites, as well as nano composites comprised of ZnO nanoparticles mixed with ferromagnetic nanoparticles. Finally, the future prospects and the extension of ME ZnO research into nanowire and nanorod composites are discussed.