TY - JOUR
T1 - Microstructure and dielectric properties of compositionally graded Ba1-xSrxTiO3 multilayer tunable capacitors
AU - Choi, Hyun Ju
AU - Woo, Jong Un
AU - Hwang, Hyun Gyu
AU - Kim, Dae Su
AU - Sanghadasa, Mohan
AU - Nahm, Sahn
N1 - Funding Information:
This work was supported by the U.S. Army International Technology Center Pacific (ITC-PAC) under Contract No. (FA5209-17-C-0009). The authors also thank the KU-KIST graduate school program of Korea University.
Funding Information:
This work was supported by the U.S. Army International Technology Center Pacific (ITC-PAC) under Contract No. (FA5209-17-C-0009). The authors also thank the KU-KIST graduate school program of Korea University.
Publisher Copyright:
© 2020
PY - 2021/4
Y1 - 2021/4
N2 - Li2O/B2O3-added Ba1-xSrxTiO3 (B1-xSxT) ceramics, where 0.2 ≤ x ≤ 0.35, were well densified at 920 °C with pure perovskite structure. The dielectric constant, tunability, and figure of merit (FOM) of B1-xSxT ceramics increased with x because of the decreasing Curie temperature (TC). The specimen with x = 0.35, whose TC was close to room temperature, exhibited a large tunability of 27.4 % and FOM of 110 at 10 kV/cm. A compositionally graded multilayer (CGML), which was sintered at 920 °C, was fabricated using B1-xSxT thick films to produce a temperature-stable tunable capacitor, and it evinced a dense microstructure and a continuous interface between the B1-xSxT thick film and the Ag electrode. This CGML capacitor showed a large tunability (51 %) and FOM (150) at 20 kV/cm. It also exhibited stable tunability (17–28 % at 10 kV/cm) at temperatures between 30–90 °C. Therefore, the B1-xSxT CGML capacitor is a suitable candidate for temperature-stable tunable capacitors.
AB - Li2O/B2O3-added Ba1-xSrxTiO3 (B1-xSxT) ceramics, where 0.2 ≤ x ≤ 0.35, were well densified at 920 °C with pure perovskite structure. The dielectric constant, tunability, and figure of merit (FOM) of B1-xSxT ceramics increased with x because of the decreasing Curie temperature (TC). The specimen with x = 0.35, whose TC was close to room temperature, exhibited a large tunability of 27.4 % and FOM of 110 at 10 kV/cm. A compositionally graded multilayer (CGML), which was sintered at 920 °C, was fabricated using B1-xSxT thick films to produce a temperature-stable tunable capacitor, and it evinced a dense microstructure and a continuous interface between the B1-xSxT thick film and the Ag electrode. This CGML capacitor showed a large tunability (51 %) and FOM (150) at 20 kV/cm. It also exhibited stable tunability (17–28 % at 10 kV/cm) at temperatures between 30–90 °C. Therefore, the B1-xSxT CGML capacitor is a suitable candidate for temperature-stable tunable capacitors.
KW - Ba1-xSrxTiO3
KW - Graded multilayer ceramics
KW - Low temperature co-fired ceramic
KW - Tape casting
KW - Temperature-stable tunable device
UR - http://www.scopus.com/inward/record.url?scp=85098164357&partnerID=8YFLogxK
U2 - 10.1016/j.jeurceramsoc.2020.12.027
DO - 10.1016/j.jeurceramsoc.2020.12.027
M3 - Article
AN - SCOPUS:85098164357
SN - 0955-2219
VL - 41
SP - 2559
EP - 2567
JO - Journal of the European Ceramic Society
JF - Journal of the European Ceramic Society
IS - 4
ER -