Proceedings Article | 5 May 2009
F. Livingston, W. Sarney, K. Niesz, T. Ould-Ely, A. Tao, D. Morse
KEYWORDS: Ferroelectric materials, Laser processing, Thin films, Nanoparticles, Pulsed laser operation, Biomimetics, Raman spectroscopy, Infrared sensors, Crystals, Modulation
The Army requires passive uncooled IR sensors for use in numerous vehicle and weapons platforms, including driver
vision enhancement (DVE), rifle sights, seeker munitions, and unattended ground sensors (UGSs) and unattended aerial
vehicles (UAVs). Recent advances in bio-inspired/biomimetic nanomaterials synthesis, laser material processing, and
sensor design and performance testing, offer the opportunity to create uncooled IR detector focal-plane arrays with
improved sensitivity, low thermal mass, and fast response times, along with amenability to low-cost, rapid prototype
manufacture. We are exploring the use of genotype-inspired, digitally-scripted laser direct-write techniques, in
conjunction with the kinetically controlled catalytic process for the growth of nanostructured multimetallic perovskites,
to develop a novel approach to the fabrication of precision patterned 2-D focal-plane arrays of pyroelectric perovskite-based
materials.
The bio-inspired growth of nanostructured, multimetallic perovskite thin-films corresponds to the use of kinetically
controlled vapor diffusion for the slow growth of pure, highly crystalline 6-nm barium titanate (BaTiO3) nanoparticles.
This unique vapor-diffusion sol-gel route enables the formation of stoichiometric cubic-phase nanoparticles at room
temperature and ambient pressure in the absence of a structure-directing template. Novel laser direct-write processing
and synchronized electro-optic pulse modulation techniques have been utilized to induce site-selective, patterned phase
transformation of microscale aggregates of the BaTiO3 nanoparticles from the non-pyroelectric cubic polymorph to the
pyroelectric tetragonal polymorph. This paper reports on our initial collaborative investigations, including
comprehensive structural characterization (XRD, TEM, and SEM) of the BaTiO3 nanoparticles and thin-films, along
with preliminary laser-induced phase transformation results.
