Ferroelectric BaTiO3 thin films were fabricated by metalorganic chemical vapor deposition (MOCVD) at atmospheric pressure. The ultrasonic spraying technique has been used to carry the source materials. The common solutions of barium-diethylhexanoate and diisopropoxy-titanium-bis-acetylacetonate in n-butanol were used as the starting materials. Since the concentration of sources can be controlled in the common solution, this method is more simple and precise than other CVD processes. The films had (110) preferred orientation with increasing temperature. The dielectric constant (ε) and the loss factor (tan
δ) of thin film deposited at 550° C were about 250 and 0.1, respectively. The leakage current density was 10-5 A/cm2 at 0.1 MV/cm.
Thermally stimulated luminescence glow curves were measured on CdS single crystals annealed in cadmium and sulphur vapour or air. The TSL glow curves were measured from liquid-nitrogen temperature to 500 K and nine glow peaks were observed at 110, 130, 190, 250, 280, 295, 320, 330 and 350 K with corresponding activation energies at 0.10, 0.18, 0.27, 0.32, 0.57, 0.82, 0.52, 0.78 and 0.83 eV. The activation energy and capture cross section for each of these peaks were calculated using a number of different analytical methods and compared with other data. The 190 K peak was the dominant feature observed in the crystal annealed in sulphur vapour so that the trap that lies 0.27 eV below the conduction band is associated with cadmium vacancies due to excess sulphur. For cadmium rich crystals, two characteristic traps appear at 280 and 350 K with depths of 0.57 and 0.83 eV. The 280 K peak was the dominant feature observed in the crystal annealed in cadmium vapour, associated with sulphur vacancies due to excess cadmium.
Pb(Zr,Ti)O 3 (PZT) films with various Zr/Ti ratios were fabricated on Pt/MgTi 2 O 5 /Si substrates by MOCVD using the ultrasonic nebulization and their characteristics were investigated. PZT thin films with various composition deposited at 400 • C were annealed in a RTA (Rapid Thermal Annealing) system at 800 • C for 30 sec to minimize the loss of the lead and improve electrical properties. The composition ratio of PZT films affected the crystallographic and electrical properties. For the films crystallized by the RTA process, the remanent polarization of PZT film with near MPB (Morphotropic phase boundary) composition was about 15 µC/cm 2 at ±5 Voltage in P-E hysteresis loops. Leakage-current density of PZT films was about 1.0 × 10 −7 A/cm 2 and 7.0 × 10 −5 A/cm 2 at +5 V and −5 V, respectively.
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