Structure evolution and dielectric behavior of polystyrene-capped barium titanate nanoparticles
| Title | Structure evolution and dielectric behavior of polystyrene-capped barium titanate nanoparticles |
| Publication Type | Journal Article |
| Year of Publication | 2012 |
| Authors | Guo HZ, Mudryk Y, Ahmad MI, Pang XC, Zhao L, Akinc M, Pecharsky VK, Bowler N, Lin ZQ, Tan X |
| Journal Title | Journal of Materials Chemistry |
| Volume | 22 |
| Pages | 23944-23951 |
| Date Published | 12 |
| Type of Article | Article |
| ISBN Number | 0959-9428 |
| Accession Number | WOS:000311522500031 |
| Keywords | BATIO3, ceramics, ferroelectric phase-transition, nanoparticles, nanowires, particles, polymer nanocomposites, size |
| Abstract | Polystyrene-capped barium titanate (BaTiO3) nanoparticles with sizes of 11 nm and 27 nm were prepared using amphiphilic star-like diblock copolymer templates. The crystal structure evolution of these nanoparticles over a wide temperature range (10-428 K) was investigated by powder X-ray diffraction. The Rietveld refinement indicates that the abrupt structural transitions observed in micron-sized powders become broad as the particle size is reduced to a few tens of nanometers. The orthorhombic phase (Amm2) is observed in the range of 10-388 K, coexisting with the rhombohedral phase (R3c) at lower temperatures and with the tetragonal phase (P4mm) at higher temperatures. At room temperature (300 K), polystyrene-capped BaTiO3 nanoparticles, both 11 and 27 nm sizes, primarily adopt the tetragonal phase, transforming to the cubic phase (Pm (3) over barm) at 398 K during heating. The phase evolution of the nanoparticles correlates well with their dielectric behavior. With the Landauer-Bruggeman effective approximation, the dielectric properties at room temperature of the BaTiO3 core were calculated and the results are in agreement with the size effect of BaTiO3 nanocrystals. |
| URL | <Go to ISI>://WOS:000311522500031 |
| DOI | 10.1039/c2jm35600g |
| Alternate Journal | J. Mater. Chem. |
