The effect of titanium excess and deficiency on the microstructure and dielectric properties of lanthanum doped Ba<sub>0.55</sub>Sr<sub>0.45</sub>Ti</sub>O<sub>3</sub> with colossal permittivity
Nurmi, Kari; Jantunen, Heli; Juuti, Jari (2018-12-19)
Kari Nurmi, Heli Jantunen, Jari Juuti, The effect of titanium excess and deficiency on the microstructure and dielectric properties of lanthanum doped Ba0.55Sr0.45TiO3 with colossal permittivity, Journal of the European Ceramic Society, Volume 39, Issue 4, 2019, Pages 1110-1115, ISSN 0955-2219, https://doi.org/10.1016/j.jeurceramsoc.2018.12.039
© 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
https://creativecommons.org/licenses/by-nc-nd/4.0/
https://urn.fi/URN:NBN:fi-fe201901303572
Tiivistelmä
Abstract
The temperature dependent dielectric properties of (Ba0.54875Sr0.44875La0.0025)Ti(1+x)O3 with both an excess and a deficiency of 0.25 mol.% TiO2 were investigated. The samples were prepared by the mixed oxide method and sintered in a conventional oven at temperatures ranging from 1400 °C to 1475 °C. The cubic perovskite structure was confirmed with XRD at room temperature. The sample with an excess of 0.25 mol.% Ti exhibited reduced grain growth while abnormal grain growth was observed for samples without Ti modification. Samples exhibited colossal permittivity for all modified compositions. With a 0.25 mol.% deficiency of Ti a permittivity over 65,000 and a tan δ under 0.05 were measured over a temperature range of −68 °C to 150 °C and a frequency range between 50 kHz and 1 MHz. This paper shows that by fine tuning the composition, materials with new, exciting and widely adjustable dielectric properties can be achieved.
Kokoelmat
- Avoin saatavuus [34150]
