Journal des sciences et de l'ingénierie des matériaux

The phase formation processes in the zone of directional laser irradiation of compacted Al2O3–TiO2–Y2O3 mixtures have been investigated. It has been established that the formed ceramic material (track) has a complex structure. Its surface layer contains α-Al2O3 as the main phase and Y2Ti2O7 inter layers. With increase in the distance from the surface of the track, the content of α-Al2O3 decreases, and the content of Y2Ti2O7 increases. The volume layers of the track contain Y2Ti2O7 as the main phase and inclusions of Y3Al5O12. The absence of Al2TiO5 or its small content is explained by the decomposition of aluminum titanate into Al2O3 and TiO2 under the conditions of rapid cooling of eutectic melt. Released titanium oxide takes part in the formation of the Y2Ti2O7 phase.

We investigated the effects of the rotational speed in the spin coating process for growing the BZT thin film. In this process, the rotational speed is taken to be 2000 rpm, 3000 rpm and 4000 rpm while the number of layer is kept constant in five layers. We also discuss the effect of the layers number in the growing of the BZT thin films. For this purpose, we take the layers number to 5, 10 and 15 layers and take the constant rotational speed of 4000rpm. In order to characterize the formed BZT thin film, the composition, crystal structure and morphological tests are performed. We found that the increasing of the rotational speed then the deposited material in the Si substrate is decreased. As a result, the X-ray intensity in certain orientation is also decreased which is indicates that the probability to form the crystal in a certain orientation is influenced by deposited material in the Si substrate. The measured grains size of the BZT thin film almost similar for the three rotational speeds. However, in the variation of layer numbers, the grain size is increasing as the increasing of layers number.