Structural and magnetic properties of a series of low doped Zn$_{1-x}$Co$_x$O thin films deposited from Zn and Co metal targets on (0001) Al$_2$O$_3$ substrates

TL;DR

This study explores how low levels of cobalt doping affect the structural and magnetic properties of ZnO thin films grown on sapphire substrates, revealing a strong dependence on Co concentration.

Contribution

It provides new insights into the relationship between Co doping levels and the structural/magnetic properties of ZnO thin films prepared by pulsed laser deposition.

Findings

Lattice parameters vary with Co concentration.

Magnetization depends on Co doping level.

Strain effects influence film properties.

Abstract

We report on the synthesis of low doping Zn$_{1-x}$Co$_x$O ($0<x<0.1$) thin films on (0001)-Al$_2$O$_3$ substrates. The films were prepared in an oxidizing atmosphere, using the pulsed laser deposition technique starting from Zn and Co metallic targets. We first studied the influence of the strains of ZnO and their stuctural properties. Second, we have investigated the structural and the magnetic properties of the Zn$_{1-x}$Co$_x$O films. We show that at low doping, the lattice parameters and the magnetization of the Zn$_{1-x}$Co$_x$O films depend strongly on the Co concentration.