Hu-Yong Tian

Preparation of PZT thick films by one-step firing sol-gel process

Abstract A one step firing process was used in preparing PZT(53/47) thick films to prevent the film cracking. Films with a single layer thickness over 0.6 μm have been prepared. XRD and SEM studies were carried out to verify the crystal growth mechanism in the firing process. The microstructures, crystallinity, ferroelectric and dielectric properties of the films were compared with those of the films prepared by the conventional sol-gel firing process. The influences of lead excess and film thickness on the film properties were also studied.

Spectroscopic Ellipsometry of BaxSr1—xTiO3 Thin Films Prepared by the Sol–Gel Method

Stoichiometric Ba x Sr 1-x TiO 3 (BST) thin films with various values of x were prepared on Si(100) substrates by the sol-gel method. The influence of Sr content on the structure and the optical properties was studied by X-ray diffraction (XRD) and spectroscopic ellipsometry (SE) in the UV-visible region. The measured SE spectra were analyzed with an appropriate procedure to accurately determine the thickness and the optical constants of thin films. It has been found that the optical constants of the BST films are functions of the film composition. The optical bandgap energy increases with the increasing of Sr content.

The influence of Y-dopant on the properties of BST films derived from a sol-gel process

Abstract The optical and dielectric properties of Y-doped Ba0.7Sr0.3 TiO3 thin films were investigated. The strong correlation was observed between the dopant concentration and materials properties. The optical band gap energy decreases with Y-dopant in BST thin films, whereas there was an increase of the band gap energy as the Y-dopant concentration increases. The dielectric constant decreases when the Y-concentration increases from 1 to 10 mol%.

Synthesis, dielectric characteristic, and microstructure of acetate-based (Ba,Sr)TiO3 thin films

A modified sol-gel process with acetate based precursor solutions for Sr-doped barium titanate thin films is presented. A four-step heating procedure was employed to prepare the Ba0.8Sr0.2TiO3 thin films. The thermal decomposition and crystallization temperatures of the precursors were determined by means of FTIR, TGA/DTA, and XRD measurements. The nonlinear C-V characteristics are due to strong depletion that can not originate from the BST/electrode interface, but must come internally from the BST films.