scholarly journals Dramatic Influence of A-Site Nonstoichiometry on the Electrical Conductivity and Conduction Mechanisms in the Perovskite Oxide Na0.5Bi0.5TiO3

2015 ◽  
Vol 27 (2) ◽  
pp. 629-634 ◽  
Author(s):  
Ming Li ◽  
Huairuo Zhang ◽  
Stuart N. Cook ◽  
Linhao Li ◽  
John A. Kilner ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Perovskite Oxide ◽  
Conduction Mechanisms ◽  
A Site

Synthesis, structural and electrical conductivity of half-metallic perovskite oxide La2CrNiO6

2021 ◽  
Author(s):  
Tushar Kanti Bhowmik ◽  
Md Sariful Sheikh ◽  
Anup Pradhan Sakhya ◽  
Alo Dutta ◽  
T. P. Sinha
Keyword(s):  
Electrical Conductivity ◽  
Perovskite Oxide ◽  
Half Metallic

Microstructure and electrical conductivity of A-site fully stoichiometric Na0.5+xBi0.5−xTiO3−δ with different Na/Bi ratios

2019 ◽  
Vol 45 (9) ◽  
pp. 11438-11447 ◽  
Author(s):  
Xiyong Chen ◽  
Mingxin Zhou ◽  
Junzuo Shi ◽  
Tianquan Liang ◽  
Jie Zeng ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
A Site

Investigation of dryland salinity using the electrical image method

Soil Research ◽  
1999 ◽  
Vol 37 (4) ◽  
pp. 623 ◽  
Author(s):  
R. I. Acworth
Keyword(s):  
Electrical Conductivity ◽  
Salt Content ◽  
Image Method ◽  
Dryland Salinity ◽  
Conductivity Variation ◽  
South Wales ◽  
Electrical Imaging ◽  
Profile Line ◽  
Conductivity Anomalies ◽  
A Site

Electrical imaging is a 2-dimensional investigation method that can be used to rapidly determine subsurface conductivity variation. In dryland salinity studies, electrical imaging is used to define the vertical extent of high electrical conductivity zones first identified using electromagnetic (EM) profiling equipment. Field techniques are described using 25 or 50 electrodes, connected to a resistance meter by a multi-core cable, to obtain images at a variety of electrode separations. The model of electrical conductivity variation obtained by an inversion of the field data is shown to agree very well with the results of detailed field investigations, including data from soil sampling, 1 : 5 extract analysis, and borehole electrical conductivity logging. Results are described from the Liverpool Plains at Yarramanbah Creek and Round Island, where a thick sequence of smectite clay overlies sands and gravels. The image clearly identifies zones of high salt content in the clay which have been sampled and logged using borehole measurements of electrical conductivity. Results are also described from a dryland salinity area in the upper part of Dicks Creek catchment on the Southern Tablelands of New South Wales. These data show the extent of clay overlying bedrock and correlate very well with the results of 1 : 5 extract analysis from shallow piezometers along the profile line. Electrical imaging is an appropriate follow-up method for the investigation of electrical conductivity anomalies first identified by EM profiling and is advisable before drilling at a site to optimise the location of piezometers.

scholarly journals Impact of A-Site Cation Deficiency on Charge Transport in La0.5−xSr0.5FeO3−d

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5990
Author(s):  
Oleg V. Merkulov ◽  
Ruslan R. Samigullin ◽  
Alexey A. Markov ◽  
Mikhail V. Patrakeev
Keyword(s):  
Electrical Conductivity ◽  
Charge Transport ◽  
Effective Means ◽  
Nonlinear Dependence ◽  
Cationic Vacancy ◽  
Ceramic Surface ◽  
X Ray Diffraction ◽  
Cation Deficiency ◽  
Oxygen Ion ◽  
A Site

The electrical conductivity of La0.5−xSr0.5FeO3−δ, investigated as a function of the nominal cation deficiency in the A-sublattice, x, varying from 0 to 0.02, has demonstrated a nonlinear dependence. An increase in the x value from 0 to 0.01 resulted in a considerable increase in electrical conductivity, which was shown to be attributed mainly to an increase in the mobility of the charge carriers. A combined analysis of the defect equilibrium and the charge transport in La0.5−xSr0.5FeO3−δ revealed the increase in the mobility of oxygen ions, electrons, and holes by factors of ~1.5, 1.3, and 1.7, respectively. The observed effect is assumed to be conditioned by a variation in the oxide structure under the action of the cationic vacancy formation. It was found that the cation deficiency limit in La0.5−xSr0.5FeO3−δ did not exceed 0.01. A small overstep of this limit was shown to result in the formation of (Sr,La)Fe12O19 impurity, which even in undetectable amounts reduced the conductivity of the material. The presence of (Sr,La)Fe12O19 impurity was revealed by X-ray diffraction on the ceramic surface after heat treatment at 1300 °C. It is most likely that the formation of traces of the liquid phase under these conditions is responsible for the impurity migration to the ceramic surface. The introduction of a cation deficiency of 0.01 into the A-sublattice of La0.5−xSr0.5FeO3−δ can be recommended as an effective means to enhance both the oxygen ion and the electron conductivity and improve ceramic sinterability.

scholarly journals Tuning the Electrical and Thermoelectric Properties of N Ion Implanted SrTiO3 Thin Films and Their Conduction Mechanisms

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Anuradha Bhogra ◽  
Anha Masarrat ◽  
Ramcharan Meena ◽  
Dilruba Hasina ◽  
Manju Bala ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Transport Properties ◽  
Thermoelectric Properties ◽  
Temperature Regime ◽  
Electrical Transport ◽  
Ion Beam ◽  
Temperature Range ◽  
Conduction Mechanisms ◽  
Band Conduction

Abstract The SrTiO3 thin films were fabricated by pulsed laser deposition. Subsequently ion implantation with 60 keV N ions at two different fluences 1 × 1016 and 5 × 1016 ions/cm2 and followed by annealing was carried out. Thin films were then characterized for electronic structure, morphology and transport properties. X-ray absorption spectroscopy reveals the local distortion of TiO6 octahedra and introduction of oxygen vacancies due to N implantation. The electrical and thermoelectric properties of these films were measured as a function of temperature to understand the conduction and scattering mechanisms. It is observed that the electrical conductivity and Seebeck coefficient (S) of these films are significantly enhanced for higher N ion fluence. The temperature dependent electrical resistivity has been analysed in the temperature range of 80–400 K, using various conduction mechanisms and fitted with band conduction, near neighbour hopping (NNH) and variable range hopping (VRH) models. It is revealed that the band conduction mechanism dominates at high temperature regime and in low temperature regime, there is a crossover between NNH and VRH. The S has been analysed using the relaxation time approximation model and dispersive transport mechanism in the temperature range of 300–400 K. Due to improvement in electrical conductivity and thermopower, the power factor is enhanced to 15 µWm−1 K−2 at 400 K at the higher ion fluence which is in the order of ten times higher as compared to the pristine films. This study suggests that ion beam can be used as an effective technique to selectively alter the electrical transport properties of oxide thermoelectric materials.

Sign in / Sign up

Export Citation Format

Share Document