Dielectric behavior of copper tantalum oxide

被引：65

作者：

Renner, B ^{[1
]}

Lunkenheimer, P ^{[1
]}

Schetter, M ^{[1
]}

Loidl, A ^{[1
]}

Reller, A ^{[1
]}

Ebbinghaus, SG ^{[1
]}

机构：

[1] Univ Augsburg, Inst Phys, D-86159 Augsburg, Germany

来源：

JOURNAL OF APPLIED PHYSICS | 2004年 / 96卷 / 08期

关键词：

D O I：

10.1063/1.1787914

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

A thorough investigation of the dielectric properties of Cu2Ta4O12, a material crystallizing in a pseudocubic, perovskite-derived structure is presented. We measured the dielectric constant and conductivity of single crystals in an exceptionally broad frequency range up to gigahertz frequencies and at temperatures from 25 to 500 K. The detected dielectric constant is unusually high (reaching values up to 10(5)) and almost constant in a broad frequency and temperature range. Cu2Ta4O12 possesses a crystal structure similar to CaCu3Ti4O12, the compound for which such an unusually high dielectric constant was first observed. An analysis of the results using a simple equivalent circuit and measurements with different types of contact revealed that extrinsic interfacial polarization effects, derived from surface barrier capacitors are the origin of the observed giant dielectric constants. The intrinsic properties of Cu2Ta4O12 are characterized by a (still relatively high) dielectric constant in the order of 100 and by a charge transport via the hopping conduction of the Anderson-localized charge carriers. (C) 2004 American Institute of Physics.

引用

页码：4400 / 4404

页数：5

共 23 条

[1] Separation of grain boundary effects and intrinsic properties in perovskite-like Gd0.6Y0.4BaCo2O5.5 using high-frequency dielectric spectroscopy -: art. no. 184403 [J].