TY - JOUR
T1 - Highly ordered mesoporous magnesium niobate high-κ dielectric ceramic: Synthesis, structural/mechanical characterization and thermal stability
AU - Tolu, Elisa
AU - Garroni, Sebastiano
AU - Pellicer, Eva
AU - Sort, Jordi
AU - Milanese, Chiara
AU - Cosseddu, Piero
AU - Enzo, Stefano
AU - Baró, Maria Dolors
AU - Mulas, Gabriele
PY - 2013/9/4
Y1 - 2013/9/4
N2 - The synthesis of a highly ordered mesoporous ternary Mg-Nb oxide by the Evaporation Induced Self-Assembly (EISA) method is presented for the first time. The as-prepared material shows 2D-hexagonal pore periodicity, with unimodal pore size distribution centered at 5.5 nm, and a large surface area (169 m 2 g-1). The mechanical properties, determined by means of nanoindentation, are consistent with the presence of ordered domains of honeycomb-like hexagonal pore arrangements, in agreement with electron microscopy observations and N2 sorption isotherm analyses. The dielectric constant of the mesoporous sample, measured at room temperature in the frequency range 1 kHz to 1 MHz, is rather high (κ ∼ 25 at 1 MHz) and correlates well with the κ value of the bulk and the porosity level of this material. Moreover, the thermal stability of the mesoporous magnesium niobate is investigated after air-annealing treatments at different temperatures. While a significant decrease of the surface area is observed for TANN = 650 °C, the mesostructure fully collapses after annealing at 800°C. © 2013 The Royal Society of Chemistry.
AB - The synthesis of a highly ordered mesoporous ternary Mg-Nb oxide by the Evaporation Induced Self-Assembly (EISA) method is presented for the first time. The as-prepared material shows 2D-hexagonal pore periodicity, with unimodal pore size distribution centered at 5.5 nm, and a large surface area (169 m 2 g-1). The mechanical properties, determined by means of nanoindentation, are consistent with the presence of ordered domains of honeycomb-like hexagonal pore arrangements, in agreement with electron microscopy observations and N2 sorption isotherm analyses. The dielectric constant of the mesoporous sample, measured at room temperature in the frequency range 1 kHz to 1 MHz, is rather high (κ ∼ 25 at 1 MHz) and correlates well with the κ value of the bulk and the porosity level of this material. Moreover, the thermal stability of the mesoporous magnesium niobate is investigated after air-annealing treatments at different temperatures. While a significant decrease of the surface area is observed for TANN = 650 °C, the mesostructure fully collapses after annealing at 800°C. © 2013 The Royal Society of Chemistry.
U2 - https://doi.org/10.1039/c3tc30500g
DO - https://doi.org/10.1039/c3tc30500g
M3 - Article
VL - 1
SP - 4948
EP - 4955
JO - Journal of Materials Chemistry C
JF - Journal of Materials Chemistry C
SN - 2050-7526
ER -