Magnetic properties of ZnO(Co) nanocrystals

The aim of the present work is to study the magnetic properties of nanocrystals of ZnO(Co) prepared by two methods of synthesis. We used the microwave assisted hydrothermal synthesis and traditional wet chemistry method followed by calcination. The detailed structural characterization was performed by means of X-ray diffraction and micro-Raman spectroscopy measurements. The magnetic properties were studied by means of AC susceptibility chi. All samples demonstrated Curie-Weiss behavior at higher temperatures. For calcination process, the negative values of the Curie-Weiss theta temperature were observed indicating the predominance of antiferromagnetic interactions. For samples prepared by hydrothermal synthesis, we observed the breakdown of predominance of antiferromagnetic interactions. (C) 2013 Elsevier B. V. All rights reserved.