Characterization of electrical properties of n-conducting barium titanate as a function of dc-bias and ac-voltage amplitude by application of impedance spectroscopy

2015 ◽  
Vol 19 (8) ◽  
pp. 2439-2444 ◽  
Author(s):  
W. Preis ◽  
J. Hofer ◽  
W. Sitte
2020 ◽  
Vol 10 (18) ◽  
pp. 6576
Author(s):  
Manuel Vázquez-Nambo ◽  
José-Antonio Gutiérrez-Gnecchi ◽  
Enrique Reyes-Archundia ◽  
Wuqiang Yang ◽  
Marco-A. Rodriguez-Frias ◽  
...  

The physicochemical characterization of pharmaceutical materials is essential for drug discovery, development and evaluation, and for understanding and predicting their interaction with physiological systems. Amongst many measurement techniques for spectroscopic characterization of pharmaceutical materials, Electrical Impedance Spectroscopy (EIS) is powerful as it can be used to model the electrical properties of pure substances and compounds in correlation with specific chemical composition. In particular, the accurate measurement of specific properties of drugs is important for evaluating physiological interaction. The electrochemical modelling of compounds is usually carried out using spectral impedance data over a wide frequency range, to fit a predetermined model of an equivalent electrochemical cell. This paper presents experimental results by EIS analysis of four drug formulations (trimethoprim/sulfamethoxazole C14H18N4O3-C10H11N3O3, ambroxol C13H18Br2N2O.HCl, metamizole sodium C13H16N3NaO4S, and ranitidine C13H22N4O3S.HCl). A wide frequency range from 20 Hz to 30 MHz is used to evaluate system identification techniques using EIS data and to obtain process models. The results suggest that arrays of linear R-C models derived using system identification techniques in the frequency domain can be used to identify different compounds.


2021 ◽  
Author(s):  
Marwa Jebli ◽  
Nejeh Hamadoui ◽  
chaker rayssi ◽  
Jemai Dhahri ◽  
Mouna Ben Henda ◽  
...  

Abstract This report typically discusses the Voltage-Stability (V-S) of the electrical properties of a new perovskite oxide, Ba0.97La0.02Ti1-xNb4x/5O3 (noted BLT, BLT0.9Nb0.08) ceramics which have been meticulously studied. The ceramics typically exhibited a low rise in the real and imaginary parts of the complex impedance on the application of small field levels (up to 5 V). These accurate data, at a low voltage threshold, properly designate a hole-generation process which becomes active. These values considered using AC impedance spectroscopy, nonetheless, were relatively decreased with increasing Nb concentration, as well as increased by this application of a DC bias. For each sample, the complex impedance plot displayed a single impedance semicircle, identified over the high and low frequencies. The equivalent circuit configuration was typically fitted using the Electrochemical Impedance Spectroscopy (EIS) spectra analyzer. Importantly, the electrical properties of our both compounds deduced from the complex electric modulus show a conduction process due to the short-range mobility of charge carriers. An excellent addition of Niobium to some considerable extent can inhibit the grain growth. Conspicuously, the substitution of Nb5+ ions for Ti4+ on B sites leads to the noticeable increase of a band gap. These findings supplied critical insights into the electric mechanisms in BT-based ceramics.


Author(s):  
Jacques Sawadogo ◽  
Jean Boukari Legma

This study is inscribed in the framework of the valorization of traditional kitchen utensils recycled from aluminum waste in Burkina Faso. In fact, these traditional kitchen utensils made of recycled aluminum alloys occupy a very important place in Burkina Faso’s kitchen. The effect of foods for consumption on its local utensils was studied using the non-stationary technique and electrochemical impedance spectroscopy. For this purpose, a sample of utensil has been deducted on traditional production site. The corrosion behavior of the recycled aluminum alloy ok know chemical composition was evaluated by analyzing the impedance spectra obtained at the open circuit potential, in the salt media titrated at 3 g·L−1 and rice. Modeling electrical properties by using of a simple equivalent circuit made it possible to interpret the results obtained by impedance spectroscopy. The results showed a susceptibility to pitting corrosion and were confirmed by the electrochemical impedance spectroscopy method.


Author(s):  
Gustavo Moreno González-Teran ◽  
Andrea Ceja-Fernandez ◽  
Rosario Galindo-González ◽  
José Marco Balleza-Ordaz

Objectives. The electrical impedance spectroscopy (EIS) is relatively new technique used in medicine. The main problems that should be solved are its low resolution and that it fails to distinguish between tissue types, so some kind of the contrast should be applied. Magnetical nanoparticles have been used for imaging and other medical applications. For that reason, our research group decided to analyse the changes of electrical properties of chicken muscle tissue caused by three different types of metal nanoparticles at 50KHz. Methodology. Bio-Logic Science Instruments SP-150 was used as EIS device. Three different particles were analysed: two types of nanomagnetite (NM1 and NM2) and one of Gold particles (GNP). NM1 and NM2 samples were synthetized by coprecipitation and combustion method, respectively. GNP were synthetized by Turkevich method. Nanoparticles were characterized by SEM and RAMAN spectroscopy. Four needles were placed in each chicken breast to connect the EIS device. Measurements were obtained from each chicken breast at basal stage and after being injected with nanoparticles. Data was analyzed by bode graphics (module and phase). Contribution. The major changes of electrical properties of tissue were evidenced by using NM1 and GNP.


Sign in / Sign up

Export Citation Format

Share Document