Microwave dielectric properties of single-crystal quantum paraelectrics KTaO3 and SrTiO3 at cryogenic temperatures -: art. no. 104111
Microwave dielectric properties of single-crystal quantum paraelectrics KTaO3 and SrTiO3 at cryogenic temperatures -: art. no. 104111
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DOI：
10.1063/1.1905789
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发表时间：
2005-05-15
影响因子：
3.2
通讯作者：
Boatner, LA
中科院分区：
文献类型：
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作者：
Geyer, RG;Riddle, B;Boatner, LA
在低温下测量了KTaO_3和SrTiO_3单晶初发量子铁电体的微波介电性能。在4 ~ 300 K的温度范围内，圆柱形样品被用作TE 0 n1模和准TE 011模介质谐振器。考虑了测量谐振结构的传导损耗，作为频率和温度的函数，因此评估的介电损耗的不确定性为+/-5%。测量真实的介电常数，精度为+/-0.5%。评估的真实的导电性KTaO 3和SrTiO 3表现出没有铁电转变，并保持顺电低至5 K，与软模式稳定。KTaO 3在3 GHz时的介电损耗角正切值在5.4 K时为4.2 x 10（-5），在77 K时为8.9 x 10（-5），在300 K时为1.4 x 10（-4），而SrTiO 3在5.4 K时为3.4 x 10（-3），在77 K时为2.4 x 10（-4），在300 K时为3.8 x 10（-4）。复介电常数的测量结果进行了比较，从修改后的Devonshire唯象模型的理论预测。(c)2005年美国物理学会。
Microwave dielectric properties of single-crystal incipient quantum ferroelectrics, KTaO3 and SrTiO3, have been measured at cryogenic temperatures. Cylindrical specimens were used as TE0n1-mode and quasi-TE011-mode dielectric resonators at temperatures ranging from 4 to 300 K. Conductive losses of the measurement resonant structures were taken into account, both as a function of frequency and temperature, so that uncertainties in the evaluated dielectric losses were +/- 5%. The real permittivity was measured with an accuracy of +/- 0.5%. The evaluated real permittivities of KTaO3 and SrTiO3 exhibit no ferroelectric transition, and remain paraelectric down to 5 K, consistent with soft-mode stabilization. Dielectric loss tangent values of KTaO3 at 3 GHz were 4.2 x 10(-5) at 5.4 K, 8.9 x 10(-5) at 77 K, and 1.4 x 10(-4) at 300 K, while those of SrTiO3 were 3.4 x 10(-3) at 5.4 K, 2.4 x 10(-4) at 77 K, and 3.8 x 10(-4) at 300 K. Results of the complex permittivity measurements are compared with theoretical predictions from a modified Devonshire phenomenological model. (c) 2005 American Institute of Physics.