Perovskite PMT-PT계의 강유전 특성 및 확산상전이 = Ferroelectric Properties and DPT in the Perovskite PMT-PT System

국문 초록 (Abstract)

Perovskite 구조의 PMT-PT계 고용체를 precursor columbite를 이용한 산화물 혼합법으로 제작하여 결정립의 성장과 상전이 현상을 분석하였다. $1250^{\circ}C$에서 4시간 유지하여 제작한 시편의 소결밀도는 이론밀도의 97% 이상이었고, 완전한 perovskite phase를 형성하였다. 치밀하게 소결 처리된 시편의 결정립의 크기는 $6\sim8{\mu}m$로 측정되었다. PMT-PT 고용체계는 복합 강유전 고용체의 전형적인 P-E 이력현상과 강한 진동수 분산특성이 관찰되었다. 특히 PMT가 70% 이하인 조성은 상전이 온도 이상에서도 자발분극이 완전히 소멸하지 않는 relaxor 특성을 보였으며, 유전상수와 유전손실의 큰 진동수 의존성을 보였다.

다국어 초록 (Multilingual Abstract)

Ferroelectric properties of the PMT-PT were also studied from the temperature dependence of hysteresis loops using a method slightly modified from Sawyer-Tower's. Dielectric, pyroelectric and piezoelectric properties of the ceramics in the system PMT-PT were investigated. The resulted densities of the PMT-PT ceramics system were greater than 97 % of the theoretical value. As observed SEM micrograph of the fracture surfaces of the PMT-PT ceramics system, the average grain sizes were increased about 3-5 ${\mu}m$ to 6-8 ${\mu}m$ with increasing sintering temperature. The specimens with PT<0.30 for PMT-PT solid solution system exhibited the dielectric and pyroelectric properties of a typical relaxor ferroelectrics. The composition with the maximum dielectric constant exhibits relatively superior pyroelectric and piezoelectric properties.

참고문헌 (Reference)

1 "The Am. Ceram. Soc. 95th. Annual Metting Short Course, Dielectric Ceramics"

2 G. A. Smolenskii, "Sov. Phys" 2584 : 1961

3 G .A. Smolenskii, "Sov. Phys" 150 : 1959

4 G. A. Smolenskii, "Sov. Phys" 1429 : 1959

5 B. Sahoo, "Proc. of ISSS 134"

6 B. Noheda, "Physical Review B"

7 A. W. Searcy, "Materials Science Research 21, Ceramic Microstructures '86 Role of Interfaces" Plenum Press 1986

8 S. L. Swartz, "Mat. Res" 17 (17): 1982

9 G. A. Smolensky, "Jpn. J. Appl" 28 (28): 1970

10 G. Shirane, "J. Phys. Soc" 7 (7): 1952

11 B. Jaffe, "J. Appl" 25 (25): 1954

12 G. S. Snow, "J. Am. Ceram" 272 (272): 1967

13 S. M. Pilgrim, "J. Am. Ceram" 72 (72): 1989

14 K. Okazaki, "J. Am. Ceram" 56 (56): 1973

15 S. L. Swartz, "J. Am. Ceram" 67 (67): 1984

16 C. Kittel, "Introduction to Solid State Physics 6th" John Wiley & Sons 1986

17 L. E. Cross, "Ferroelectrics 76"

18 V. V. Kirillov, "Ferroelectrics 5"

19 J. Kuwata, "Ferroelectrics 37"

20 Y. J. Kim, "Ferroelectrics 195"

21 L. E. Cross, "Ferroelectrics 151" 1994

22 R. W. Whatmore, "Ferroelectrics 118"

23 S. N. Gvasaliya, "Crystallography Reports 49"

24 I. A. Santos, "Condens" 11733 : 2001

25 R. E. Loehman, "Characterization of Ceramics" Butterworth-Heinemann 1993

26 W. E. Lee, "Ceramic Microstructures ; Property Control by Processing" Chapman and Hall 1990

27 K. Uchino, "Ceram" 65 (65): 1986