DC AND AC CONDUCTIVITY OF SODIUM MOLYBDENUM PHOSPHATE-GLASSES

被引:14
作者
TARSIKKA, PS
SINGH, B
机构
[1] Department of Physics, Punjabi University, Patiala
关键词
D O I
10.1016/0022-3093(90)90266-O
中图分类号
TQ174 [陶瓷工业]; TB3 [工程材料学];
学科分类号
0805 ; 080502 ;
摘要
The effects of sodium and molybdenum in sodium-molybdenum phosphate glasses have been studied by dc and ac conductivity measurements over a wide temperature range. Results indicate that the contribution of electronic conduction to dc conductivity increases with molybdenum concentration. It is difficult to separate the ionic from electronic conduction. Greaves variable range hopping for dc conductivity has been observed to be valid at intermediate temperatures. The value of the electron wave function decay constant α has been evaluated to be 1.05 Å-1 (assuming N(EF ≈ 1019 eV-1 cm-3). These values are in agreement with those estimated using a tunnelling model for ac conductivity at 77 K. Values of s evaluated from the relation σac(ω) = Aωs are comparable to those evaluated from the hopping over barrier model. The dielectric relaxation frequency for these glasses has been observed to be about 1.5 kHz in the temperature range of 100-200 K. © 1990.
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页码:221 / 228
页数:8
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