The Transactions of the Korean Institute of Electrical Engineers C (대한전기학회논문지:전기물성ㆍ응용부문C)

The Korean Institute of Electrical Engineers (대한전기학회)
권호 표지

Dielectric Properties of SCT Ceramics with the Sintering Temperature and the Thermal Treatment Time

소결온도와 열처리시간에 따른 SCT 세라믹스의 유전특성

  • Published : 2001.11.01

Abstract

ln this paper, the $Sr_{l-x}Ca_xTiO_3(0\leqx\leq0.2)-based$ grain boundary layer ceramics were fabricated to measure dielectric properties with the sintering temperature and the thermal treatment time. The sintering temperature and time were $1420~15206{\circ}C$, 4hours, and the thermal treatment temperature and time of the specimen were $l150^{\circ}C$, 1, 2, 3hours, respectively. The structural and the dielectric properties were investigated by SEM, X-ray, HP4194A and K6517. The average grain size was increased with increasing the sintering temperature, but it decreased up to 15mo1% with increasing content of Ca. X-ray diffraction analysis results showed that all specimens were the cubic structure, and the main peaks were moved to right and the lattice constant were decreased with increasing content of Ca. The appropriate thermal treatment time and temperature of CuO to obtain dielectric properties of $\varepsilon_r>50000,\; tan \delta<0.05\; and \;\DeltaC<\pm10%$ were 2hrs and $l150^{\circ}C$, respectively.

Keywords

grain boundary layer;the lattice constant;the thermal treatment time;the cubic structure

File

Download PDF

References

  1. T. Hirata, K. Ishioke and M. Kitajima, 'Vibrational Spectroscopy and X -ray Diffraction of Perovskite Compounds Sn-xMxTi03 (M=Ca,Mg;O~x~l)', J. Solid State Chem., 124, 353-359, 1996 https://doi.org/10.1006/jssc.1996.0249
  2. Nobutatsu Yamaoka, '$SrTiO_3$-Based Boundary-Layer Capacitors', Ceramic bulletin, 65[5], 1149-1152, 1986
  3. M. Mcqurarrie, 'Structural Behavior in the system (Ba,Ca,Sr)$TiO_3$ and Its Relation to Certain Dielectric Characteristics', J. Am. Ceram. Soc., 38, 444, 1955 https://doi.org/10.1111/j.1151-2916.1955.tb14545.x
  4. J. M Herbert/Ceramic Dielectrics and Capacitors', Gordon and Breach Scienec Publishers, pp.202-209, 1985
  5. M. Ceh, D. Kolar and L. Golic,'The phase Diagram of $CaTiO_3-SrTiO_3$', J. Solid State Chem., 68, 68, 1987 https://doi.org/10.1016/0022-4596(87)90286-6
  6. Qing Zou et al,' Microstructure and Grain Boundary Structure of $Na^+$-Diffused (Sr : Ca)$TiO_3$ CapacitorVaristor Ceramics', J. Am. Ceram. Soc. 78[1] 58-64, 1995 https://doi.org/10.1111/j.1151-2916.1995.tb08360.x
  7. P. E. C. Franken et al, 'Microstructure of $SrTiO_3$ Boundary-Layer Capacitor Material', J. Am. Ceram. Soc. 64[12] 687-690, 1981 https://doi.org/10.1111/j.1151-2916.1981.tb15886.x
  8. F. POIGNANT et al,'A TEM study of grain boundaries in internal boundary layer capacitors based on donor-doped (Sr . Ca) $TiO_3$ ceramics', journal of materials science Materials Electronics. 8 139 -146, 1997 https://doi.org/10.1023/A:1018533827407
  9. Takahiro T AKADA et al,' The Effects of Additives for a (Sr,Ca)(Ti,Nb)$TiO_3$ Boundary Layer CapacitiveVaristor on the Microstructure and Electronic Properties', J. Am. Ceram. Soc. 103[3] 251-256, 1995
  10. S. Waku, M. Uchidata, and K. Kiuchi, 'Study on the (Ba,Sr)Ti03 Boundary Layer Ceramic Dielectrics', Rev. Elect. Comm. Lab., 18(9-10), pp.681-693, 1970
  11. Nobutatsu Yamaoka, Masaru Masuyama, and Masami Fukui, '$SrTiO_3$-Based Boundary Layer Capacitor Having Varistor Characteristics', Ceramic Bulletin, 62[6], 698-703, 1983
  12. G. V. Planer, and R. M. Glaister, British Pat., 861, 346, 1961
  13. S. Waku, 'Studies on the Boundary Layer Ceramic Capacitor', Rev. Elect. Comm. Lab., 15(9-10), pp. 689-716, 1967