Papers by Author: Agata Lisińska-Czekaj

Abstract: Piezoelectric transformer (PT) is a combination of piezoelectric actuator and transducer, which serve as the primary side and the secondary side respectively. In the present study the disk – shaped (of 20 mm in diameter and 0.6 mm in thickness), unipoled radial mode piezoelectric transformer based on modified PZT-type solid solution was custom designed and fabricated. Different input and output area ratios of the PT were studied, namely: 21, 4, 1. The electrical properties like voltage step-up ratio, output power and temperature rise were measured for PT operating at the first resonance frequency. With the driving voltage of 20 VRMS, the 3 W output power, 165 VRMS output voltage an temperature rise of 20 0C was obtained for PT with the input/output area ratio of 1. The voltage step-up ratio of 12.5 was obtained for PT with input/output area ratio of 21.

Abstract: The present study is devoted to synthesis and investigation of photoluminescence in the nanosized Bi4Ti3O12 (BTO) thin films. The randomly oriented BTO thin films have been obtained by a modified hybrid sol-gel process. Bismuth nitrate and titanium (IV) butoxide were used as the starting materials. The thin films were deposited on silicon, glass and stainless steel by spin coating and crystallized by the conventional thermal annealing at temperature T=650°C. Formation of the layer perovskite-type structure of the orthorhombic symmetry was confirmed by X-ray diffraction method. Conservation of the chemical composition was investigated by energy dispersive spectroscopy. The UV luminescence has been observed in BTO thin films at room temperature. Results on luminescence excitation and emission in bismuth titanate thin films are given in the present paper.