Maxim Lebedev

Microstructure and Electrical Properties of Lead Zirconate Titanate (Pb(Zr52/Ti48)O3) Thick Films Deposited by Aerosol Deposition Method

Lead zirconate titanate (PZT) films with a thickness of more than 10 µm were prepared by the aerosol deposition method and their microstructure and chemical composition were investigated by transmission electron microscopy (TEM) and energy dispersive X-ray spectra (EDX) analysis. A damage layer was observed at the interface between PZT and the Si substrate during the deposition. The microstructure of the as-deposited film at room temperature consisted of randomly oriented small crystallites with sizes of less than 40 nm and large crystallites of 100 nm to 300 nm size, which were observed in the primary powder. The Pb/Ti/Zr ratio along the film stacking direction and around the grain boundaries was almost the same as that observed inside the crystallites and the primary powder with a morphotropic phase boundary composition of (Pb(Zr0.52Ti0.48)O3). The marked improvement of the electrical properties observed in the deposited films after annealing was mainly due to the crystal growth of small crystallites.

Influence of Carrier Gas Conditions on Electrical and Optical Properties of Pb(Zr,Ti)O3 Thin Films Prepared by Aerosol Deposition Method.

Transparent Pb(Zr, Ti)O3 (PZT) thin films with over 1 µm thickness were deposited by the aerosol deposition method (ADM). The transparency of the PZT thin film deposited at room temperature strongly depended on the kinds of carrier gases and the particle flow velocity. The color of the film became black if He gas was used as a carrier gas, and became transparent using N2, O2 or air gases, which were difficult to electrically discharge during the impacting of particles. The transmittance values in the 0.5–0.8 µm wavelength region of as-deposited 2-µm-thick PZT thin films on indium tin oxide (ITO) substrate were 70–80%. After annealing at 600°C, the remanent polarizations and the coercive fields of PZT thin films were 36 µC/cm2 and 89 kV/cm, respectively. With increasing carrier gas velocity, the remanent polarization decreased and the coercive field increased.

Powder Preparation in Aerosol Deposition Method for Lead Zirconate Titanate Thick Films

The influence of a pre-process for a starting powder in the deposition of ferroelectric thick films using the aerosol deposition method (ADM) was investigated. When a dry-milling procedure was introduced to the preparation of the ferroelectric powder, the deposition rate of ADM increased significantly up to 30-fold and reached 73 µm/min for a 5 mm2 area. However, density and electrical properties of the thick film decreased. If heat treatment at 800°C for 4 h was additionally introduced to the pre-process of the starting powder, the deposition rate increased up to 7–10-fold as compared with that for a starting powder and the electrical properties were improved from Pr=20 µC/cm2 at Ec=50 kV/cm to 32 µC/cm2 at Ec=45 kV/cm.

High-speed optical microscanner driven with resonation of Lam Waves using Pb(Zr.Ti)O3 thick films formed by aerosol deposition

A high-performance optical microscanner with a resonance frequency over 20 kHz and a scan angle (peak-to-peak value) over 30° in atmospheric ambient, was successfully fabricated by deposit piezoelectric materials at a high rate by the AD method onto a metal scanner structure, which was fabricated by mechanical machining. The scanner is applicable to SVGA high-resolution display of 800×600 or more. This method is a powerful tool for realizing ceramic integration with metal components.

Effects of annealing and poling conditions on piezoelectric properties of Pb(Zr0.52,Ti0.48)O3 thick films formed by aerosol deposition method

Abstract Lead zirconate titanate (PZT) thick films were formed on several kinds of substrates by impact consolidation of PZT ultrafine particles through an aerosol deposition method. The PZT layers were shown to have a high breakdown voltage of about 700xa0kV/cm after annealing at temperatures from room temperature to 1000°C. After annealing at 600–1000°C for 1xa0h in air and poling at 250°C 40xa0kV/cm for 30xa0min, the layers had good piezoelectric properties: – d 31 ∼100xa0pm/V, which did not change with fatigue testing up to 10 9 cycles.

Magnetic properties of Sm-Fe-N thick film magnets prepared by the aerosol deposition method

This paper describes magnetic properties of Sm-Fe-N films prepared by an aerosol deposition method. The films with thickness of 3-45 /spl mu/m were obtained by the deposition within 10 min and the deposition rate was estimated as approximately 2-10 /spl mu/m/min. The Sm-Fe-N films showed relatively high micro Vickers hardness in the range from 500 to 700. The remanence of the Sm-Fe-N films was approximately 0.4 T, which was lower than that of initial host powders. However, almost of all samples showed higher coercivities around 1.8 T.

Effect of Thickness on the Piezoelectric Properties of Lead Zirconate Titanate Films Fabricated by Aerosol Deposition Method

Dense lead zirconate titanate (PZT) films in the thickness range of 2–100 µm were fabricated by the aerosol deposition method (ADM) to study the thickness dependence of the ferroelectric characteristics. The recovery of ferroelectricity by annealing is uniform inside a thick PZT film. Breakdown electrical field increased with decreasing thickness of the film and was over 1 MV/cm for a 4-µm-thick PZT film. Increase of the internal stress for thinner PZT films led to the increase of the coercive field and breakdown electrical strength.

Electro-optical properties of (Pb,La)(Zr,Ti)O3 films prepared by aerosol deposition method

Electro-optically active and highly transparent lanthanum-modified lead zirconate titanate [PLZT, Pb0.91La0.09(Zr0.65Ti0.35)O3] films over 1 µm thick were deposited directly on glass substrates using an aerosol deposition method. An optical transmittance of 70% at the wavelength of 800 nm was obtained for a 4.5-µm-thick PLZT film with a reflection loss of 20% at the film and substrate surfaces. A quadratic electro-optical response with a slim loop was observed, consistent with the expected bulk response. The quadratic electro-optical coefficient was 2.5×10-18 m2/V2, comparable to that of films deposited on buffer layers using a sol-gel method. These results indicate that aerosol deposition provides a superior method for depositing the layers of optical devices.

Theoretical and Experimental Investigation of Propagation of Guide Waves in Cylindrical Pipe Filled with Fluid

Cylindrical pipes are widely used in industries such as nuclear power plants and micro total analysis systems (µTAS). The nondestructive evaluation (NDE) of such pipes is therefore crucial. NDE and ultrasonic flowmeters can be used to characterize pipes filled with fluid. Lafleur and Shields [J. Acoust. Soc. Am. 97 (1995) 1435] and Pan et al. [J. Acoust. Soc. Am. 113 (2003) 3209] theoretically and experimentally investigated a pipe filled with fluid, but they only considered the axi-symmetrical mode. Commonly used ultrasonic transducer or laser ultrasonic methods, however, also generate non-axi-symmetrical mode guide waves. Here, guide waves propagating in a cylindrical pipe filled with fluid were theoretically investigated. The results were used to develop a computer program for calculating the phase velocity of guide waves. The calculation results were then compared with experimental results.

Aerosol Deposition Method for Preparation of Lead Zirconate Titanate Thick Layer at Low Temperature –Improvement of Electrical Properties by Irradiation of Fast Atom Beam and Plasma

The improvement of the electrical properties of a lead zirconate titanate (PZT) layer and the reduction of the processing temperature in the aerosol deposition method (ADM) using irradiation of a fast atom beam (FAB) and plasma were investigated. The remanent polarization of the PZT layer deposited with oxygen FAB irradiation on a stainless steel substrate and annealed at 400°C for 10 min was 15 µC/cm2 which is 2 times higher than that without FAB irradiation. The dielectric permittivity (e) at 1 kHz–1 MHz was also improved by 25–45% by FAB irradiation for PZT layers, both as-deposited at room temperature and annealed at up to 400°C.