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ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY STUDY OF CORROSION INHIBITION OF MODIFIED LIGNOSULPHONATE FOR CARBON STEEL
CH Yi,XQ Qiu,DJ Yang,HM Lou,
C.H. Yi
,X.Q. Qiu,D.J. Yang and H.M. LouCollege of Chemical and Energy Engineering,South China University of Technology,Guangzhou,China

金属学报(英文版) , 2005,
Abstract: The corrosion inhibition for carbon steel in circulating cooling water by modified lignosulphonate has been investigated using electrochemical impedance spectroscopy technique. Results show that the inhibition efficiency of modified lignosulphonate GCL2 is a great improvement on that of lignosulphonate. The maximum inhibition efficiency of GCL2 reaches 99.21% at the concentration of 400mg·L-1 at 303K. The corrosion inhibition of GCL2 is attributed to forming adsorption film on the metal surface for the electrochemical impedance spectroscopy in GCL2 solution shows more than one time-constant. Moreover, results also indicate that it is more efficient in stirring solution than in still solution for GCL2 because the constant of adsorption in stirring solution is much larger than that in still solution. The adsorption of inhibitor GCL2 follows Langmuir's adsorption isotherm.
Electrical characterization by impedance spectroscopy of Zn7Sb2O12 ceramic
Nobre, Marcos A. de Lima;Lanfredi, Silvania;
Materials Research , 2003, DOI: 10.1590/S1516-14392003000200007
Abstract: impedance spectroscopy technique was used to investigate the electric properties of zn7sb2o12, an electroceramic with inverse spinel type structure. the electric characterization of the zn7sb2o12 semiconducting ceramic was performed at temperature from 250 to 550 °c, in the frequency range from 5 hz to 13 mhz. zinc antimoniate phase was synthesized by the polymeric precursors method. the bulk resistance curve as a function of temperature exhibits a thermistor behavior with negative temperature coefficient. the bulk conductivity follows the arrhenius law with two linear branches of different slopes positioned at around a region of transition, 450 °c > t > 350 °c. the activation energy values at low temperature (< 350 °c) and high temperature (> 450 °c) are equals to 0.78 and 0.61 ev, respectively. the existence of a phase transition limiting these regions is discussed.
Electrical characterization by impedance spectroscopy of Zn7Sb2O12 ceramic
Nobre Marcos A. de Lima,Lanfredi Silvania
Materials Research , 2003,
Abstract: Impedance spectroscopy technique was used to investigate the electric properties of Zn7Sb2O12, an electroceramic with inverse spinel type structure. The electric characterization of the Zn7Sb2O12 semiconducting ceramic was performed at temperature from 250 to 550 degreesC, in the frequency range from 5 Hz to 13 MHz. Zinc antimoniate phase was synthesized by the polymeric precursors method. The bulk resistance curve as a function of temperature exhibits a thermistor behavior with negative temperature coefficient. The bulk conductivity follows the Arrhenius law with two linear branches of different slopes positioned at around a region of transition, 450 degreesC > T > 350 degreesC. The activation energy values at low temperature (< 350 degreesC) and high temperature (> 450 degreesC) are equals to 0.78 and 0.61 eV, respectively. The existence of a phase transition limiting these regions is discussed.
Cyclic Voltammetry and Impedance Spectroscopy Behavior Studies of Polyterthiophene Modified Electrode  [PDF]
Naima Maouche,Belkacem Nessark
International Journal of Electrochemistry , 2011, DOI: 10.4061/2011/670513
Abstract: We present in this work a study of the electrochemical behaviour of terthiophene and its corresponding polymer, which is obtained electrochemically as a film by cyclic voltammetry (CV) on platinum electrode. The analysis focuses essentially on the effect of two solvents acetonitrile and dichloromethane on the electrochemical behaviour of the obtained polymer. The electrochemical behavior of this material was investigated by cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The voltammograms show that the film of polyterthiophene can oxide and reduce in two solutions; in acetonitrile, the oxidation current intensity is more important than in dichloromethane. The impedance plots show the semicircle which is characteristic of charge-transfer resistance at the electrode/polymer interface at high frequency and the diffusion process at low frequency. 1. Introduction As other conjugated conducting polymers, polythiophene and its oligomers can be polymerized from their monomers in solutions by electrochemical methods. The electrochemical synthesis is advantageous method: polymers are formed in the doped state; films generally possess interesting electrochemical and good semiconductor properties [1] and relatively good stability in air for both the neutral and oxidised states [2–7]. The mechanism of the electropolymerisation of conducting polymers and polyheterocycles occurred by the coupling via α-α bonding of monomer radical cation after its oxidation at the electrode, and the protons are removed from dihydrodication leading to neutral species [8–10]. As the dimer is more easily oxidized than the monomer, it is immediately oxidized. The chain elongation occurs by the addition of new monomer radical cation leading to polymerization and forms the insoluble polymeric species, which subsequently deposits onto the electrode [11]. Conducting polymer-modified electrodes have been widely investigated because of their potential application in areas such as electrocatalysis [12, 13], sensors [14, 15], corrosion [16–18], batteries [19, 20], electronic displays, and devices [21–24]. In our previous work [25], we have studied the role of P3T in corrosion of stainless steel; the results were important and show effectively that the film of P3T will decrease the corrosion rate. In this paper, we are interested in performing an electrochemical characterisation of P3T films electrochemically synthesized, in two organic solvents: acetonitrile (CH3CN) and dichloromethane (CH2Cl2), at platinum substrates. We want to show how the medium of the analysis is
boldmath Characterization of the BaBiO3-doped BaTiO3 positive temperature coefficient of a resistivity ceramic using impedance spectroscopy with Tc=155℃
袁昌来,刘心宇,周昌荣,许积文,杨云
中国物理 B , 2011,
Abstract: BaBiO3-doped BaTiO3 (BB-BT) ceramic, as a candidate for lead-free positive temperature coefficient of resistivity (PTCR) materials with a higher Curie temperature, has been synthesized in air by a conventional sintering technique. The temperature dependence of resistivity shows that the phase transition of the PTC thermistor ceramic occurs at the Curie temperature, Tc=155 ℃, which is higher than that of BaTiO3 ( ≤ 130 ℃). Analysis of ac impedance data using complex impedance spectroscopy gives the alternate current (AC) resistance of the PTCR ceramic. By additional use of the complex electric modulus formalism to analyse the same data, the inhomogeneous nature of the ceramic may be unveiled. The impedance spectra reveal that the grain resistance of the BB-BT sample is slightly influenced by the increase of temperature, indicating that the increase in overall resistivity is entirely due to a grain-boundary effect. Based on the dependence of the extent to which the peaks of the imaginary part of electric modulus and impedance are matched on frequency, the conduction mechanism is also discussed for a BB-BT ceramic system.
Study of the La0.2235 Pr0.2235 Nd0.2235 Sr0.33 MnO3 ceramic by X ray diffraction and impedance spectroscopy  [cached]
Rhouma F. I. H.,Dhahri A.,Farhat N.,Dhahri J.
EPJ Web of Conferences , 2012, DOI: 10.1051/epjconf/20122900023
Abstract: The La0.2235 Pr0.2235 Nd0.2235 Sr0.33 MnO3 (LPNSM) ceramic has been obtained from oxides by sintering in air. The electrical properties of this material have been studied using ac impedance spectroscopy technique over a wide range of temperatures and frequency. Furthermore, a detailed analysis of the impedance spectrum suggested that the electrical properties of the material are strongly temperature dependent and have a good correlation with the sample microstructure in different temperature ranges.
Origin of ferroelectric-like hysteresis loop of CaCu3Ti4O12 ceramic studied by impedance and micro-Raman spectroscopy  [PDF]
Sungmin Park,Hyosang Kwon,Doyoung Park,Hyeonsik Cheong,Gwangseo Park
Physics , 2011,
Abstract: Ferroelectric-like hysteresis loops of CaCu3Ti4O12 (CCTO) ceramic have been observed. We found that this unusual feature does not arise from the displacement of the Ti ions in the TiO6 octahedron, but apparently comes from the charges at the grain boundaries which consist of a CuO layer. The relaxation time of 2.9 milliseconds by the charges from the grain boundary, nearly corresponding to the inverse P - V sampling frequency of 1kHz, has been found in the impedance spectrum. According to the micro-Raman mapping, the CuO layer is found in the grain boundary and is perfectly distinguished from the CCTO grain.
Impedance spectroscopy studies on lead free (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 ceramics
Ahcène Chaouchi,Sadia Kennour
Processing and Application of Ceramics , 2012,
Abstract: The AC complex impedance spectroscopy technique has been used to obtain the electrical parameters of polycrystalline sample of (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 in a wide frequency range at different temperatures. This sample was prepared by a high temperature solid-state reaction technique and single phase formation was confirmed by X-ray diffraction technique. This study was carried out by the means of simultaneous analysis of impedance, modulus, and electrical conductivity. The Cole-Cole (Nyquist) plots suggest that the grains and grain boundaries are responsible in the conduction mechanism of the material at high temperature. The ColeCole (Nyquist) plot studies revealed the presence of grain and grain boundary effect at 485 °C. On the other hand, it showed only the presence of grain boundary component of the resistivity at 535 °C. Complex impedance analysis indicated the presence of non-Debye type dielectric relaxation. The bulk resistance of the material decreases with rise in temperature similar to a semiconductor, and the Cole-Cole (Nyquist) plot showed the negative temperature coefficient of resistance (NTCR) character of (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3. The value of activation energy is found to be 0.7433 eV, which suggests that the conduction may be the result of defect and charge carriers present in the materials.
Determination of the ionic transport numbers of lanthanum gallate materials by impedance spectroscopy and modified EMF method  [cached]
Pe?a-Martínez, J.,Marrero-López, D.,Ruiz-Morales, J. C.,Nú?ez, P.
Boletín de la Sociedad Espa?ola de Cerámica y Vidrio , 2008,
Abstract: A combination of impedance spectroscopy and a modified electromotive force method (emf) were used to evaluate the ionic transport numbers and the overall conductivity of several doped lanthanum gallate materials, i.e. La0.9Sr0.1Ga1-xMgxO3-δ (x=0.05-0.30), La0.9A0.1Ga0.8Mg0.2O3-δ (A=Sr, Ba and Ca) and La0.9Sr0.1Ga0.8Mg0.2-yCoyO3-δ (y=0.015 and 0.045). La0.9Sr0.1Ga0.8Mg0.2O2.85 (LSGM) sample showed the maximum ionic transport number in the temperature range 900-1173 K, around 0.99 in both O2/air and H2/air gradients. La conductividad total y los números de transporte iónico de las composiciones, basadas en el galato de lantano, La0,9Sr0,1Ga1-xMgxO3-δ (x=0,05-0,30), La0,9A0,1Ga0,8Mg0,2O3-δ (A=Sr, Ba, Ca) y La0,9Sr0,1Ga0,8Mg0,2-yCoyO3-δ (y=0.015; 0,045) fueron estudiadas mediante una combinación de técnicas de espectroscopia de impedancia compleja y fuerza electromotriz (fem). La composición La0,9Sr0,1Ga0,8Mg0,2O2,85 (LSGM) presenta el mayor número de transporte iónico, concretamente 0,99 en el rango de temperaturas 900-1173 K, tanto en gradiente de O2/aire como de H2/aire.
Electrical Conduction in Ceramic by Complex Impedance/Modulus Spectroscopy  [cached]
Ansu Kumar Roy,Kamal Prasad,Ashutosh Prasad
ISRN Ceramics , 2013, DOI: 10.1155/2013/369670
Abstract:
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