Element specific measurements of the structural properties and magnetism of CoxZn1-xO

We present studies on CoxZn1-xO films grown by reactive magnetron sputtering in comparison to pulsed laser deposition (PLD) grown samples. By means of X-ray-linear-dichroism we proved very good local structural properties for both cation types of our films. X-ray-diffraction measurements corroborated good crystalline quality although the high structural perfection of PLD grown films was not achieved by reactive magnetron sputtering. Magnetization measurements with a superconducting quantum interference device showed similar paramagnetic behaviour for samples of both types of growth processes. To mimic the role of oxygen vacancies, reduced oxygen partial pressure was used in case of magnetron sputtered films. This resulted in reduced structural quality accompanied by altered magnetic properties like an open hysteresis and field cooled/zero field cooled separation, as well as magnetic resonances observed at room temperature, which we take as an indication for clustering of the dopant. (C) 2008 Elsevier B. V. All rights reserved.