Photoinduced Metallic Particle Growth on Single-Crystal Relaxor Ferroelectric Strontium Barium Niobate

The photochemical growth of metallic particles on relaxor ferroelectric tetragonal tungsten bronze strontium barium niobate (SBN) is reported in this work. Silver and gold particles were deposited on the unpoled (001) and the (100) surfaces of single-crystal SBN:60 and SBN:61 via reduction of silver nitrate and gold chloride solutions, respectively, under UV illumination. Wavelength-dependent experiments reveal that differences in particle deposition on the unpoled (001) and (100) surfaces are primarily due to the optical absorption of the UV light and not due to the surface termination or local ferroelectric domain structure. Particle deposition on electric field-poled (001) surfaces is enhanced on positive domains and is suppressed on negative domains. Unusual particle deposition was observed on the perimeter of domains obtained from incomplete switching of the unpoled (001) surface. On the basis of our experimental observations, we propose a band diagram for the SBN interface and we discuss the underlying mechanisms influencing the particle deposition process.