Low temperature dielectric properties and NTCR behavior of the BaFe0.5Nb0.5O3 double perovskite ceramic

2020 ◽  
Vol 22 (5) ◽  
pp. 2986-2998 ◽  
Author(s):  
Vijay Khopkar ◽  
Balaram Sahoo

The microstructure and low-temperature dielectric properties of lead-free BaFe0.5Nb0.5O3 ceramics exhibiting a negative temperature coefficient of resistance behavior.

2015 ◽  
Vol 3 (3) ◽  
pp. 1317-1324 ◽  
Author(s):  
Yanrong Wang ◽  
Bin Liu ◽  
Songhua Xiao ◽  
Han Li ◽  
Lingling Wang ◽  
...  

A catalytically activated hydrogen sensor is obtained based on Pd decorated WO3 nanoplates constructed by a solvothermal method.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
M. Mirigliano ◽  
S. Radice ◽  
A. Falqui ◽  
A. Casu ◽  
F. Cavaliere ◽  
...  

AbstractWe report the observation of non-metallic electrical conduction, resistive switching, and a negative temperature coefficient of resistance in nanostructured gold films above the electrical percolation and in strong-coupling regime, from room down to cryogenic temperatures (24 K). Nanostructured continuous gold films are assembled by supersonic cluster beam deposition of Au aggregates formed in the gas phase. The structure of the cluster-assembled films is characterized by an extremely high density of randomly oriented crystalline nanodomains, separated by grain boundaries and with a large number of lattice defects. Our data indicates that space charge limited conduction and Coulomb blockade are at the origin of the anomalous electrical behavior. The high density of extended defects and grain boundaries causes the localization of conduction electrons over the entire investigated temperature range.


2012 ◽  
Vol 101 (13) ◽  
pp. 133111 ◽  
Author(s):  
Li Yang ◽  
Haiyang Lin ◽  
Tao Wang ◽  
Shiyong Ye ◽  
Mingwang Shao ◽  
...  

2008 ◽  
Vol 84 (4) ◽  
pp. 47007 ◽  
Author(s):  
Abhishek Pandey ◽  
Chandan Mazumdar ◽  
R. Ranganathan ◽  
Molly De Raychaudhury ◽  
T. Saha-Dasgupta ◽  
...  

1973 ◽  
Vol 51 (18) ◽  
pp. 3152-3155 ◽  
Author(s):  
Huw O. Pritchard

It is shown that previously calculated nonequilibrium rate constants for the dissociation of H2 and D2 appear to approach a rotationally averaged equilibrium expression at low temperature. This equilibrium form of the rate expression itself has an Arrhenius temperature coefficient for dissociation which is significantly less than the dissociation energy, and the corresponding recombination rate constant has a negative temperature coefficient. The reasons for this are explained.


2019 ◽  
Vol 13 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Rutuparna Das ◽  
Ram Choudhary

In this paper, dielectric relaxor, impedance, AC conductivity and electrical modulus of double perovskite Nd2NiMnO6, prepared by a solid state reaction method and sintered at 1250?C, have been reported in the wide temperature (25-150?C) and frequency (1 kHz-1MHz) ranges. From the preliminary X-ray structural analysis, it is found that the structure of the material is monoclinic. In the study of the temperature dependence of the dielectric constant, the relaxor behaviour of the material is observed. Such type of behaviour is explained by a modified Curie-Weiss and a Vogel-Fulcher law. By analysing Nyquist plots, the existence of grain and grain boundary effects is established. The non-Debye type of relaxation is investigated by the analysis of complex impedance and the modulus data. From the study of impedance data, it is found that the grain resistance is reduced with the increase in temperature indicating the existence of negative temperature coefficient of resistance (NTCR) behaviour in the material which also matches with temperature versus AC conductivity plots. From these results, it may be concluded that this compound may have extreme potential for different high temperature applications.


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