Nd, La, K, Na이 치환된 $Pb(Mg_{1/3}Nb_{2/3})O_3$ 세라믹의 구조 및 유전 성질에 관한 연구 |
권숙화, 박휴범, 김정1, 홍영식, 김시중 |
고려대학교 화학과 1서남대학교 화학과 |
Structural and Dielectric Properties of $Pb(Mg_{1/3}Nb_{2/3})O_3$ Ceramics Substituted by Nd, La, K and Na |
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ABSTRACT |
The structural and dielectric properties of Pb(Mg1/3Nb2/3)O3 ceramics substituted by Nd3+, La3+, K+ and Na+ were studied over 0~50 at.% substituent content. The 1 : 1 ordering behavior of Mg2+ and Nb5+ ions in the B site sublattice was observed in Nd3+-and La3+-modified compounds. The degree of ordering was increased with Nd3+, La3+ content in the compounds. But K+-or Na+-modified compounds did not exhibit the ordering behavior. This was explained by charge and size effect of A and B site cations and oxygen vacancies. As the mole fractions of substituent increased, the maximum values of dielectric constants were rapidly decreased and the phase transitions were broadened. Phase transition temperature was correlated with the covalency of A-O and B-O bonding. |
Key words:
$Pb(Mg_{1/3}Nb_{2/3})O_3$, Perovskite, 1 : 1 ordering |
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