Effects of packing fraction and bond valence on microwave dielectric properties of A2+B6+O4 (A2+: Ca, Pb, Ba; B6+: Mo, W) ceramics
Effects of packing fraction and bond valence on microwave dielectric properties of A2+B6+O4 (A2+: Ca, Pb, Ba; B6+: Mo, W) ceramics
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DOI：
10.1016/j.jeurceramsoc.2009.12.018
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发表时间：
2010-05-01
影响因子：
5.7
通讯作者：
Cernik, Robert J.
中科院分区：
文献类型：
--
作者：
Kim, Eung Soo;Chun, Byung Sam;Cernik, Robert J.
A（2+）B（6+）O（4）（A（2+）Ca，Pb，Ba; B（6+）Mo，W）陶瓷的填充率和键价的函数关系。在800-1100 ℃烧结3 h的A（2+）B（6+）O（4）样品中，检测到具有四方白钨矿结构的单相，虽然Ba 2+的离子极化率比Ca 2+小，但BaB 6 + O 4的介电常数K值比CaB 6+小O 4这些结果可以归因于由于有效tonic尺寸的填充分数的变化。Q.f值在很大程度上取决于填充分数，以及理论密度的百分比。样品的共振频率温度系数（TCF）受氧的键价影响。在1000 ℃下烧结3 h的CaMoO 4样品的K为10.8，Q.f为76.990 GHz，TCF为-22.8 ppm/degrees C，分别为（C）2010 Elsevier Ltd All rights reserved
Microwave dielectric properties of A(2+)B(6+)O(4) (A(2+) Ca, Pb, Ba; B6+ Mo, W) ceramics were investigated as a function of packing fraction and bond valence For A(2+)B(6+)O(4) specimens sintered at 800-1100 degrees C for 3 h, a single phase with a tetragonal scheelite structure was detected, and the theoretical density was higher than 93% throughout the composition Although the ionic polarizability of Ba2+ ton was lamer than that of Ca2+ the dielectric constant (K) of BaB6+O4 showed a smaller value than that of CaB6+O4 These results could be attributed to changes of the packing fraction due to the effective tonic size The Q.f value was largely dependent on the packing fraction, as well as the percentages of theoretical density. The temperature coefficients of the resonant frequencies (TCFs) of the specimens were affected by the bond valence of oxygen The specimens of CaMoO4 sintered at 1000 degrees C for 3 h showed the K of 10.8, Q.f of 76.990 GHz and TCF of -22.8 ppm/degrees C, respectively (C) 2010 Elsevier Ltd All rights reserved