scholarly journals Modulation in Electric Conduction of PVK and Ferrocene-Doped PVK Thin Films

2022 ◽  
Vol 3 (1) ◽  
pp. 53-62
Author(s):  
Hari Chandra Nayak ◽  
Shivendra Singh Parmar ◽  
Rajendra Prasad Kumhar ◽  
Shailendra Rajput
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Frequency Dependence ◽  
Relative Permittivity ◽  
Frequency Dispersion ◽  
Frequency Region ◽  
Dielectric Parameter ◽  
High Frequency Region ◽  
Casting Technique ◽  
Tan Δ

In this article, the dielectric properties of poly (9-vinylcarbazole) (PVK) and ferrocene-doped PVK thin films are studied. The thin films were grown by the isothermal solution casting technique. Dielectric properties of grown films were studied as function of ferrocene concentration, frequency, and temperature. The relative permittivity (ε′) is increased with increasing ferrocene percentage (~1%) due to the free charge carriers. The relative permittivity decreases for higher ferrocene percentage (~2%). However, the relative permittivity of PVK and ferrocene-doped PVK samples remains almost constant for studied temperature range (313–413 K). The frequency dependence of tan δ for all samples is studied. The frequency dependence of dielectric parameter exhibits frequency dispersion behavior, which suggests all types of polarization present in the lower frequency range. The loss tangent (tanδ) values are larger at higher temperatures in the low frequency region. However, the tan δ values at different temperatures are almost similar in the high frequency region. It is observed that the relative permittivity is maximum, dielectric loss is minimum, and AC conductivity is minimum for 1% ferrocene doped PVK as compared to pure PVK and 2% ferrocene doped PVK samples.

Frequency dependence of the dielectric properties of La-doped Pb(Zr0.35Ti0.65)O3 thin films

2003 ◽  
Vol 83 (14) ◽  
pp. 2892-2894 ◽  
Author(s):  
Z. G. Zhang ◽  
D. P. Chu ◽  
B. M. McGregor ◽  
P. Migliorato ◽  
K. Ohashi ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Frequency Dependence ◽  
La Doped

AC CONDUCTIVITY AND DIELECTRIC PROPERTIES OF MANGANESE DOPED LAYERED Na1.89Li0.10K0.01Ti3O7 CERAMICS

2013 ◽  
Vol 28 (01) ◽  
pp. 1350200
Author(s):  
SHRIPAL SHARMA ◽  
RAKESH SINGH ◽  
GEETIKA
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Properties ◽  
Chemical Synthesis ◽  
Loss Tangent ◽  
Relative Permittivity ◽  
Ac Electrical Conductivity ◽  
Conduction Mechanisms ◽  
Tan Δ ◽  
Electron Clouds ◽  
Derivatives Of

Manganese doped derivatives of polycrystalline Na 1.89 Li 0.10 K 0.01 Ti 3 O 7 bearing 0.01, 0.05 and 1.0 molar % of manganese have been prepared by chemical synthesis. The results of ac electrical conductivity studies in form of log (σT) versus 1000/T plots are reported in the frequency and temperature range of 10 kHz–1 MHz and 350–775 K, respectively. The corresponding plots have been divided into five temperature regions, I, II, III, IV and V. The various conduction mechanisms in different regions have been discussed. The nature of conductivity has been explained by proposing a model about the obtained conductivity σ(ω) which is the sum of three terms arising from three different mechanisms. Moreover, various Na–K–Li–O–Ti–O linkages in Na 2-x-y Li x K y Ti 3 O 7 materials may result special forms of electron clouds. Experimental results of the loss tangent ( tan δ) and relative permittivity (εr) versus temperature at different frequencies have been described. The results of tan δ and εr versus frequency plots at different temperature have also been given for these doped derivatives.

FREQUENCY DEPENDENCE OF THE DIELECTRIC PROPERTIES AND COERCIVE FIELD OF PbZr0.4Ti0.6O3 THIN FILMS

2006 ◽  
Vol 85 (1) ◽  
pp. 31-38 ◽  
Author(s):  
TIAN-ZHI LIU ◽  
ZHI-GANG ZHANG ◽  
DAN XIE ◽  
CHAO-GANG WEI ◽  
TIAN-LING REN ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Frequency Dependence ◽  
Coercive Field

Influence of the Grain Size on the Conduction Mechanism of Barium Strontium Titanate Thin Films

2011 ◽  
Vol 66 (12) ◽  
pp. 784-790 ◽  
Author(s):  
Ala’eddin A. Saif ◽  
Zul Azhar Zahid Jamal ◽  
Prabakaran Poopalan
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Strontium Titanate ◽  
Barium Strontium Titanate ◽  
Conduction Mechanism ◽  
Frequency Region ◽  
High Frequency Region ◽  
Debye Relaxation ◽  
Barium Strontium ◽  
Metal Insulator Metal

Sol-gel barium strontium titanate ( Ba0.6Sr0.4TiO3) thin films with different grain sizes have been successfully fabricated as metal-insulator-metal (MIM) capacitors. The perovskite structure of the material has been confirmed via X-ray diffraction (XRD). In order to correlate the effect of the grain size to the conduction mechanisms of these films, atomic force microscopy (AFM) results are presented. The grain size shows an important effect on the conduction mechanism for the films. The results show that as the grain size increases, both the impedance and the permittivity of the films decrease, whereas the conductivity shows an inverse variation. The Z* plane for all films shows two regions, corresponding to the bulk mechanism and the distribution of the grain boundaries-electrodes conduction process.M´´ versus frequency plots reveal non-Debye relaxation peaks, which are not able to be observed in the e´´ plots. Alternating current (AC) conductivity versus frequency plots show three regions of conduction processes, i.e. a low-frequency region due to direct current (DC) conduction, a mid-frequency region due to translational hopping motion, and a high-frequency region due to localized hopping and/or reorientational motion.

scholarly journals MEASURING THE DIELECTRIC PROPERTIES OF TUMOR AND BREAST PHANTOMS USED IN THE MICROWAVE FREQUENCY RANGE

2016 ◽  
Vol 4 ◽  
pp. 647-651
Author(s):  
Eva Maniakova ◽  
Dagmar Faktorova
Keyword(s):  
Dielectric Properties ◽  
Production Process ◽  
Frequency Dependence ◽  
Human Tissue ◽  
Relative Permittivity ◽  
Resonance Method ◽  
Microwave Frequency ◽  
Frequency Range ◽  
Tissue Phantoms ◽  
Breast Phantom

INTRODUCTION: This article deals with measurement of dielectric properties (relative permittivity and conductivity) of phantoms, specifically a tumor phantom and a breast phantom. We focused on the waveguide and resonance methods for the measurement of dielectric properties. The article describes the principle of these methods, and also the production process of a breast phantom and a tumor phantom. These phantoms can be used for measurements in the microwave frequency range, 8–12 GHz.OBJECTIVE: The study’s objective was to design a tumor phantom and a breast phantom, and to measure their dielectric properties. These properties must simulate human tissue.METHODS: To measure dielectric properties of human tissue, phantoms were designed using the waveguide Hippel`s method and the resonance method with a cavity resonator.RESULTS: The aim of this work was to create the phantoms that would have properties comparable to those of real tissues. Results of measurement are shown as frequency dependence of relative permittivity and conductivity for breast, breast phantom, tumor, and tumor phantom.

DIELECTRIC PROPERTIES OF PLASMA POLYMERIZED N,N,3,5 TETRAMETHYLANILINE THIN FILMS

2011 ◽  
Vol 18 (01n02) ◽  
pp. 53-60 ◽  
Author(s):  
H. AKTHER ◽  
A. H. BHUIYAN
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Relaxation Times ◽  
Electrical Conductance ◽  
Low Frequency ◽  
Ring Structure ◽  
Frequency Region ◽  
Localized States ◽  
High Frequency Region ◽  
Capacitively Coupled

Plasma polymerized thin films of aluminium/thin film/aluminium configuration were deposited at room temperature by a parallel plate capacitively coupled glow discharge reactor using N,N,3,5 tetramethylaniline (TMA) as a precursor. The infrared spectroscopic analyses revealed that plasma polymerized TMA (PPTMA) films contained an aromatic ring structure with NC and CH side groups, presence of C = O was also evident. The differential thermal analysis and thermogravimetric analysis of PPTMA thin film was thermally stable up to about 505 K. The scanning electron microscopy of PPTMA thin film showed a smooth, flawless and pinhole free surface. The capacitance and ac electrical conductance of PPTMA thin films were measured as functions of frequency (100 < f < 105 Hz) and temperature (300 < T < 450 K). The electrical conductivity is more dependent on temperature in the low frequency region than that in the high frequency region. In PPTMA thin films the conduction may be dominated by hopping of carriers between the localized states at low temperatures and thermally excited at the high temperatures. The activation energies are estimated to be about 0.05 eV in the low temperature and 0.23 eV in the high temperature. Dielectric constant decreases with the increase of frequency and that decreases with the increase of temperature but dielectric loss increases with increasing frequency with a minimum in the low frequency region. The temperature-dependence of the Cole-Cole diagram shows the existence of distribution of dielectric relaxation times in the PPTMA thin films.

scholarly journals Investigation of Surface Scaling, Optical and Microwave Dielectric Studies of Bi0.5Na0.5TiO3 thin Films

2021 ◽  
Author(s):  
Srinivas Pattipaka ◽  
Pamu D ◽  
Pundareekam Goud J ◽  
James Raju K C ◽  
Gbinda Pradhan ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Secondary Phase ◽  
Close Relation ◽  
Degree Of Crystallinity ◽  
Microwave Dielectric ◽  
Potential Applications ◽  
Tan Δ ◽  
5 Ghz

Abstract Herein, we have investigated the optical and microwave dielectric properties of Bi 0.5 Na 0.5 TiO 3 (BNT) thin films grown under different oxygen pressure ( P O2 ) using pulsed laser deposition (PLD) technique. The X-ray diffraction measurements confirms the single phase of BNT along with secondary phase and further reduction in secondary phase and increase in BNT phase with P O2 , signifies the close relation between the crystal structure and oxygen content. The shift of Raman-active TO1, TO2 and TO3 modes towards higher wavelengths and increase in mode intensity with P O2 indicating the films degree of crystallinity. The local roughness ( α loc ) of all films obtained as ~ 0.85, and the interface width ( w ) and lateral correlation length ( ξ ) of films varies with P O2 . Also, the films exhibit the increase in refractive index and reduction in optical bandgap of due to improvement in crystallinity and reduction in the oxygen vacancies. The microwave dielectric properties show a strong P O2 depends with higher dielectric constant ( ε r = 336) with lower loss (tan δ = 0.0093) at 5 GHz which show the potential applications in high frequency devices.

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