Dielectric properties and charge transport in the (Sr,La)NbO3.5-x system -: art. no. 155115

被引：33

作者：

Bobnar, V ^{[1
]}

Lunkenheimer, P ^{[1
]}

Hemberger, J ^{[1
]}

Loidl, A ^{[1
]}

Lichtenberg, F ^{[1
]}

Mannhart, J ^{[1
]}

机构：

[1] Univ Augsburg, Inst Phys, D-86135 Augsburg, Germany

来源：

PHYSICAL REVIEW B | 2002年 / 65卷 / 15期

关键词：

D O I：

10.1103/PhysRevB.65.155115

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The dielectric response of layered perovskite-related insulating SrNbO3.5 and conducting SrNbO3.41, SrNbO3.45, and La0.2Sr0.8NbO3.5 single crystals is investigated. The measurements are performed along the c axis, i.e., perpendicular to the layers, in the frequency range from 1 MHz to 1.8 GHz. The intrinsic dielectric properties could be monitored only at such relatively high measuring frequencies, since strong contact contributions at the sample-electrode interface dominate at low frequencies. In addition to the known phase transitions in the SrNbO3.5 compound, a phase transition at Tapproximate to300 K in SrNbO3.41 and SrNbO3.45 is reported here. The frequency-dependent ac conductivity in all three conducting compounds follows the universal dielectric response behavior. Together with results on the dc conductivity, this finding indicates that hopping of localized charge carriers, most likely of polaronic character, is the dominating charge-transport process. For all SrNbO3.5-x compounds, relatively high values of the dielectric constant are found.

引用

页码：1 / 8

页数：8

共 27 条

[1] DIELECTRIC AND FERROELECTRIC PROPERTIES IN THE LOW-TEMPERATURE PHASE OF STRONTIUM NIOBATE [J].