ランタンとセリウムを含む高誘電率チタン酸バリウムセラミックスの温度特性

概要

論文の詳細を見る
The dielectric temperature characteristics of the high-k (Ba_<1-x>La_x)(Ti_<1-x/4-0.05>Ce_<0.05>) O_3 ceramics (BLTC: where x=0.01 to 0.05) with diffuse phase transition (DPT) behavior at different frequencies were studied. The 'relaxor' behavior of BLTC with respect to temperature (at 1 kHz) and frequency was quantified by means of some parameters, FWHM, δ, γ, and ⊿T_<mf>′, ⊿ε_<mf>′/ε_m′, repectively. DPT behavior and thermal hysteresis effect were discussed. The results indicated that the co-doping with La and 5 at% Ce causes strong diffusion of ferroelectric phase transition of BaTiO_3 and pronounced rising of the permittivity peak (ε_m′>10000 for 0.02≤x≤0.05) in a frequency range 1 to 100 kHz. The rate that the permittivity peak shifts towards low temperature decreases slightly with increasing frequency, from 30.7℃/at% La at 1 Hz to 29.5℃/at% La at 100 kHz. This rate is faster than any BaTiO_3 dopant reported previously. The x=0.03 sample meets Y5V and Z5U specifications at 1 kHz when the thermal hysteresis effect is considered. The increase in La concent (x) can markedly suppress the dielectric loss (tan δ).
社団法人日本セラミックス協会の論文
2006-07-01