Fabrication of high-sensitivity Bi0.2-xCexSr0.5La0.3TiO3 (0
JOURNAL OF ALLOYS AND COMPOUNDS
Authors: Liu, Ting; Chen, Xuan; Zhang, Huimin; Chang, Aimin; Wu, Yiquan
Abstract
High density negative temperature coefficient (NTC) thermistor ceramics Bi(0.2-x)C(e)xSr(0.5)La(0.3)TiO(3) (0 < x < 0.05) (BCSLTO) were synthesized by the Pechini method. This work is the first to characterization analysis the excellent NTC characteristics of BCSLTO ceramics at high temperatures. BCSLTO NTC thermistor ceramics have wide operating temperature is 300 degrees C-1000 degrees C, and mild sintering conditions with the conventional sintering at 1250 degrees C. The important electrical performance parameters of BCSLTO ceramics are as follows: the resistivities at 300 degrees C, 700 degrees C, and 1000 degrees C are 3.26 x 10(9)-8.99 x 10(7) Omega cm, 2.21 x 10(5)-1.05 x 10(5) Omega cm, and 1.18 x 10(3)-1.13 x 10(3) Omega cm, respectively; the thermal constant B-300/700 is 13385.9-9408.8 K; the activity energy Ea(300/700) is 1.15-0.81 eV. The resistivity and the thermal constant B can be widely control by doping Ce. In addition, the resistivity drift improves as the Ce doping content increases (below 5%). The new high-temperature Bi0.2-xCexSr0.5La0.3TiO3 ceramic materials with mild sintering conditions, wide operating temperature and high-temperature stability can be used as potential candidates for high temperatures and harsh environments. (C) 2020 Elsevier B.V. All rights reserved.
Study the effect of gamma-ray irradiation on the optical properties of HgI2 thin film using method solvent evaporation
PHYSICA SCRIPTA
Authors: Omer, Noor K.; Zamel, Rafid S.; Hussein, Adi M. Abdul
Abstract
The effect of irradiation on optical and electrical features of (HgI2) film was done using solution method on glass substrate, with thickness of (10) mu m. The film was irradiated by Cs-137 to obtain Gamma ray at time irradiation of 48 h. The spectra absorbance and transmittance have been registered in the range (200-1000) nm. The results show that the optical band gap for (HgI2) decreased after irradiation with gamma ray, the prepared films were found to have a straight energy gap in the range of 2.2 eV before irradiation and 1.7 eV after irradiating. The calculated optical coefficients, such as absorption, extinction, refracting index were changed after irradiating with gamma ray. For the I-V characteristic, an increasing in the current after irradiation has been obtained.
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