Uniform dispersion of lanthanum hexaboride nanoparticles in a silica thin film: synthesis and optical properties.
Silica thin films containing uniformly dispersed lanthanum hexaboride (LaB₆) nanoparticles have been prepared by spin-coating a sol-gel silica solution containing cetyltrimethyl ammonium bromide (CTAB)-stabilized LaB₆ nanoparticles onto a glass substrate followed by a standard heat treatment. The production of this thin film involved three steps: (i) a CTAB-stabilized LaB₆ nanoparticle dispersion was prepared in water and then dried, (ii) the dried nanoparticles were redispersed in a small amount of water and mixed with tetraethoxyorthosilane (TEOS), ethanol, and a little acid to initiate the sol-gel reaction, and (iii) this reaction mixture was spun to produce a thin film and then was annealed. A range of techniques such as zeta potential, laser sizing, energy-filtered transmission electron microscopy (EFTEM), scanning TEM (STEM), scanning electron microscopy (SEM), and energy dispersive X-ray spectrum (EDS) were employed to characterize the particle's size, elemental composition, and stability and the optical properties of silica thin films with LaB₆ nanoparticles. On the basis of the optical transmittance and reflectance spectra of an annealed silica thin film with LaB₆ nanoparticles, the annealed thin films clearly showed positive absorption of radiation in the near infrared (NIR) region meeting a main objective of this study. A potential optical micro-electromechanical sensing system in the NIR range can be realized on the basis of this silica thin film with LaB₆ nanoparticles.
School of Electrical, Electronic and Computer Engineering, University of Western Australia, Australia. jiang@mech.uwa.edu.au
Fei
F
Jiang
Yee-Kwong
YK
Leong
Martine
M
Saunders
Mariusz
M
Martyniuk
Lorenzo
L
Faraone
Adrian
A
Keating
John M
JM
Dell
D001896:Boron Compounds / Q000737:chemistry*; D007811:Lanthanum / Q000737:chemistry*; D008422:Materials Testing; D008567:Membranes, Artificial; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D012031:Refractometry; D012822:Silicon Dioxide / Q000737:chemistry*
D001896:Boron Compounds; D008567:Membranes, Artificial; D007811:Lanthanum; D012822:Silicon Dioxide