Eutectic reaction between copper oxide and titanium dioxide

Eutectic reaction between copper oxide (CuO) and titanium dioxide (TiO2) wa s investigated by using directly Cu and TiO2 samples and by employing optic al microscopy, X-ray diffraction (XRD). scanning electron microscopy. and e lectron probe for microanalysis (EPMA). Different types of samples includin g Cu plate/TiO2 pellet samples and TiO2/Cu/TiO2 sandwiched samples were pre pared. The samples would react with each other at as considerably low. as a bout 900 degrees C in air. which is due to a eutectic reaction. The reactio n diagram was generated, in which different reaction categories were denote d at various temperatures (300- 1070 degreesC) and limes, After annealing, the weight changes normalized to the original Cu samples were also analyzed to verify the eutectic reaction. The eutectic was identified to be the CuO -TiO2 system characterized from XRD and EPMA analyses. Annealing in N-2/O-2 =9 at the same temperature as in air resulted in similar but not so drastic eutectic melting phenomena. The eutectic reaction would enhance significan tly the grain growth of TiO2 and the oxidation of Cu. The changes in the mi crostructures and the morphologies of the samples were also investigated. T he eutectic temperatures of CuO and other oxide systems were compared and d iscussed. The eutectic points as well as the phase diagram of the CuO-TiO2 system were calculated and analyzed. Several potential applications of the reactions were also proposed, (C) 2001 Elsevier Science Ltd. All rights res erved.