Crystal structure, impedance and broadband dielectric spectra of ordered scheelite-structured Bi(Sc1/3Mo2/3)O-4 ceramic
Crystal structure, impedance and broadband dielectric spectra of ordered scheelite-structured Bi(Sc1/3Mo2/3)O-4 ceramic
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有序白钨矿结构Bi(Sc1/3Mo2/3)O-4陶瓷的晶体结构、阻抗和宽带介电谱
DOI：
10.1016/j.jeurceramsoc.2017.12.044
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发表时间：
2018
影响因子：
5.7
通讯作者：
Reaney Ian M.
中科院分区：
文献类型：
--
作者：
Zhou Di;Pang Li-Xia;Wang Da -Wei;Guo Huan-Huan;Yang Fan;Qi Ze-Ming;Li Chun;Jin Biao-Bing;Reaney Ian M.
采用固相反应法制备了Bi（Sc 1/3 Mo 2/3）O 4陶瓷。它的晶体结构与白钨矿类似，具有有序结构（a = 16.9821（9），B = 11.6097（3），c = 5.3099（3）和β = 104.649（2）°），空间群为C12/C1，其中Bi 3+，Sc 3+和Mo 6+分别以−8，−6和−4配位。Bi（Sc 1/3 Mo 2/3）O 4陶瓷在915 °C下致密化，得到介电常数（εr）<$24.4，品质因数（Qf，Q= 1/介电损耗，f=谐振频率）<$48，100 GHz和谐振频率温度系数（TCF）<$−68 ppm/°C。阻抗谱显示，只有一个体积响应的电导率与活化能（Ea）为0.97 eV，这表明该化合物是电气和化学均匀的。利用宽带介电谱研究了Bi（Sc 1/3 Mo 2/3）O 4在20 Hz ~ 30 THz范围内的介电响应。ε r在20 Hz ~ GHz范围内是稳定的，只有离子和电子位移极化对εr有贡献。
Bi(Sc1/3Mo2/3)O4ceramics were prepared via solid state reaction method. It crystallized with an ordered scheelite-related structure (a = 16.9821(9) Å, b = 11.6097(3) Å, c = 5.3099(3) Å and β = 104.649(2)°) with a space group C12/C1, in which Bi3+, Sc3+and Mo6+are −8, −6 and −4 coordinated, respectively. Bi(Sc1/3Mo2/3)O4ceramics were densifiedat 915 °C, giving a permittivity (εr) ∼24.4, quality factor (Qf,Q= 1/dielectric loss,f= resonant frequency) ∼48, 100 GHz and temperature coefficient of resonant frequency (TCF) ∼ −68 ppm/°C. Impedance spectroscopy revealed that there was only a bulk response for conductivity with activation energy (Ea) ∼0.97 eV, suggesting the compound is electrically and chemically homogeneous. Wide band dielectric spectra were employed to study the dielectric response of Bi(Sc1/3Mo2/3)O4from 20 Hz to 30 THz. εrwas stable from 20 Hz to the GHz region, in which only ionic and electron displacive polarization contributed to the εr.