Lead-free piezoelectric thin films by sol-gel method : synthesis and characterization - Université Polytechnique des Hauts-de-France Accéder directement au contenu
Communication Dans Un Congrès Année : 2016

Lead-free piezoelectric thin films by sol-gel method : synthesis and characterization

Résumé

The most common piezoelectric materials are lead zirconate titanate (Pb(Zr,Ti)O3 or PZT) due to their ferroelectric and piezoelectric properties. However, due to the effects of lead toxicity, it has recently desired to develop lead-free piezoelectric materials for environmental protection. Therefore, lead-free piezoelectric materials have been attracting attention worldwide as new materials in place of PZT-based systems. Bismuth sodium titanate ceramics (Bi0.5Na0.5TiO3 or BNT) with strong ferroelectric properties (remnant polarization Pr=38 µC/cm2, Curie temperature Tc= 320°C and coercive field Ec= 73 kV/cm) and relatively high piezoelectric properties (d33=60-90 pm/V) is considered a promising lead-free piezoelectric material. The sol-gel method is widely used for the fabrication of ferroelectric thin films due to short and simple fabrication equipment. This technique offers good stoichiometry control of the film composition and good adhesion between the substrate and the coat solution. In this work Bi0.5Na0.5TiO3 thin films were prepared by a Sol-Gel/Spin-Coating process. Bismuth nitrate III penta-hydrate, sodium nitrate and titanium (IV) isopropoxide were used as starting chemical reagents to prepare a BNT precursor sol. The solution is deposited by spin coating on a Pt/Ti/SiO2/Si substrate. Then thermal processes (drying, pyrolysis and annealing) were applied; BNT films were annealed with the rapid thermal processor (RTP) which is a little different from the conventional process. In the conventional process, films are annealed at high temperatures after multiple spin-coatings, while in the RTP annealing is applied after each layer deposition in order to reduce thermal stresses. First results of piezoelectric characterizations at the macroscopic level showed promising piezoelectric response (d33=42 pm/V at 270 kV/cm). BixNa1-xTiO3 films are currently prepared with some modifications of the chemical composition (0.4 < x < 0.6) to study the influence of the A-site composition on the structural, microstructural and electrical properties.
Fichier non déposé

Dates et versions

hal-04084798 , version 1 (28-04-2023)

Identifiants

  • HAL Id : hal-04084798 , version 1

Citer

Sara Abou Dargham, Freddy Ponchel, A. Khoury, Jamal Assaad, Denis Remiens, et al.. Lead-free piezoelectric thin films by sol-gel method : synthesis and characterization. European Materials Research Society Spring Meeting, E-MRS Spring 2016, May 2016, Lille, France. ⟨hal-04084798⟩
19 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More