Effect of processing method on physical properties of Nb2O5

被引：68

作者：

Soares, M. R. N. ^{[1
]}

Leite, S. ^{[1
]}

Nico, C. ^{[1
]}

Peres, M. ^{[1
]}

Fernandes, A. J. S. ^{[1
]}

Graca, M. P. F. ^{[1
]}

Matos, M. ^{[2
]}

Monteiro, R. ^{[2
]}

Monteiro, T. ^{[1
]}

Costa, F. M. ^{[1
]}

机构：

[1] Univ Aveiro, Dept Fis & I3N, P-3810193 Aveiro, Portugal

[2] KEMET Elect Portugal, Evora, Portugal

来源：

JOURNAL OF THE EUROPEAN CERAMIC SOCIETY | 2011年 / 31卷 / 04期

关键词：

D; Niobates; B; Fibres; C. Optical properties; C. Dielectric properties; Laser Floating Zone; NIOBIUM; PHOTOCONDUCTIVITY; TEMPERATURE;

D O I：

10.1016/j.jeurceramsoc.2010.10.024

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：

Samples of Nb2O5 were prepared by laser floating zone (LFZ) technique and by solid-state reaction in order to study some of their physical properties as a function of synthesis conditions. Single crystals fibres were obtained by LFZ, while a structural orthorhombic to monoclinic phase transition was observed in samples sintered at temperature higher than 800 degrees C. Transmission optical spectroscopy and photoconductivity measurements allowed identifying a similar to 3.2 eV bandgap energy for the H-Nb2O5 monoclinic crystalline phase. Band gap shrinkage of similar to 100 meV was observed from 14K to RT. For the orthorhombic phase (T-Nb2O5), the photoconductivity measurements evidence a higher energy bandgap. The sintered samples have shown a broad recombination luminescence band at the orange/red spectral region while no luminescence was detected from the LFZ grown fibres. A dielectric constant of similar to 40 was found for the 800 degrees C and 1200 degrees C sintered pellets while that of 1000 degrees C reached four times that value. (C) 2010 Elsevier Ltd. All rights reserved.

引用

页码：501 / 506

页数：6

共 20 条

[1]

ADADUROV GA, 1974, COMBUST EXPLO SHOCK, V7, P503

[2] RAMAN-SPECTRUM OF THE HIGH-TEMPERATURE FORM OF NB2O5 [J].