Synthesis of Sr_0.5Ba_0.5Nb₂O₆ (SBN) thin films by sol-gel technique

Abstract

Tungsten bronze Sr_0.5Ba_0.5Nb₂O₆ nano-powders and thin films on platinum, Si(100), and sapphire substrates were prepared by the sol-gel route and characterized by x-ray diffraction and micro-Raman scattering techniques. The transparent and crack-free films crystallized into an orthorhombic phase at 700°C. Annealing of these films at higher temperature (∼ 750°C) for longer time yielded a mixture of ferroelectric tetragonal and a non ferroelectric orthorhombic phase. As a result, in some discrete regions of the films we could record well saturated hysteresis loops with reasonably good fatigue characteristics. Both the films and powders were completely transformed into a ferroelectric tetragonal tungsten bronze structure when annealed at 1100°C for 12 hours.

Keywords:

• SBN films
• Sol-gel
• Thin films
• Ferroelectric