ESR STUDY OF CuO BULK POWDER AND THIN FILMS

A systematic Electron Spin Resonance investigation is carried out in CuO bulk powder and thin films, after calcining them to different temperatures ranging from 100°C to 1000°C. In CuO powder, two separate signals (one broad and one sharp) were observed at calcination temperature of 500°C, for the fist time. They got intensified, came closer and amalgamated on further heating upto 800°C, indicating complete destruction of antiferromagnetic ordering in this powdered compound. In thin films of CuO, the first appearance of the signal at 200°C and its intensification and shifting on further heating indicates that in thin film form, the destruction of antiferromagnetism takes place much earlier.