LCR Measurement Research Articles

Dielectric behavior and defects of nitrogen-containing single crystal diamond films

Single crystal diamond (SCD) film, as a new substrate material, has attracted growing attention because of its low dielectric loss. The nitrogen was usually introduced into microwave plasma chemical vapor deposition (MPCVD) process in order to enhance the growth rate of SCD films. So SCD films with nitrogen were prepared by MPCVD compared with the undoped film. The impurities and defects of diamond films were characterized by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) and photoluminescence spectroscopy (PL). The dielectric behavior of SCD films was measured using the LCR measurement in the frequency range of 1 kHz to 110 MHz. The results indicate that the primary dielectric loss in SCD films is conductivity loss and space charge polarization below 1 MHz, while the main dielectric loss is dipole orientation polarization and electronic relaxation polarization in the frequency range of 1 MHz to 110 MHz. Point defects like substitutional N+, NV− and SiV− exert a significant influence on polarization loss. This is essential to improve the growth of SCD with excellent dielectric properties.

Structural, electrical and magnetic studies on Zn doped MnFe2O4 nanoparticles with via Sol-Gel approach

A manganese ferrite (MnFe2O4) nanoparticle is prepared through sol-gel method. The various concentration of Zn (x = 0.0, 0.1, 0.3, 0.5, 0.7, 0.9) was added to the initial solutions. Through X-Ray diffraction examinations results confirmed the cubic spinel structure of Mn1-xZnxFe2O4 and have larger crystallite size. The functional analysis is obtained through Fourier transform infrared spectroscopy (FTIR) analysis and it is indicated that Fe-O, Mn-O, and Zn-O vibrational bands. The optical analysis carried out through UV–visible spectrometer. The surface features with morphology and its content of elements in the samples were found through scanning electron microscope (SEM) with energy dispersive (EDAX) analysis. The energy analysis carried out through Xray Photo electro absorption (XPS) analysis. The detailed magnetic characteristics of the resulting samples such as cohersivity (Hc), magnetization (Ms), retentivity (Hr), squareness ratio (SQR) and anisotripic constant (Ki) were found through vibrating sample magnetometer (VSM), shows good magnetic property, multi grain wall and the strong dependents of Zn . The dielectric related parameters like dielectric constant for real and imaginary components, loss tangent with AC conductivity with respect to applied frequency are enhanced dielectric constant and at the same time it reduces the dielectric loss tangent discussed through LCR measurement. The electrochemical behaviour of the samples was tested through cyclic voltameter setup. Finally, concluded with their merits and demerits.

Structural, electrical and magnetic studies on CoFe2O4 nanoparticles with polyvinylalcohol (PVA) via Sol-Gel approach

Cobalt ferrite (CoFe2O4) nanoparticles were synthesized using sol–gel method from cobalt nitrate; iron nitrate as precursor materials with the chelating agent PVA in water (2.5, 5.0, 7.5, 10.0 and 12.5 %) is added. Through X-ray diffraction (XRD) examinations, the crystallite size and single phase of the ferrite samples were studied. The functional and active analysis is found through Fourier transform infrared (FTIR) studies. The optical analysis carried out through UV–visible spectrometer and the absorption is found. The surface features and its content of elements were analyzed through SEM with EDAX analysis. The larger saturation magnetization at 12.5 % were recorded through vibrating sample magnetometer (VSM). The dielectric behavior recorded at room temperature from LCR measurement. The electrochemical behavior like V/I, impedance, scan rate and phase angle obtained through cyclic voltameter setup. The observed results with all the physical parameters with the influence of presence of PVA are discussed and interpreted extensively.

Dielectric Parametric Study in Electrospun PLZT/PVDF Nanocomposite Membranes

Electrospun lead lanthanum zirconate titanate (PLZT)/polyvinylidene fluoride(PVDF) nanocomposite-based membranes were fabricated using a traditional electrospinning process. Scanning electron microscopy (SEM) was utilized to observe the surface morphology of the electrospun nanofiber membrane. The dielectric parameters of the nanocomposite membranes, such as permittivity, electric modulus, ac conductivity, and Impedance in the frequency range of 103 -106 Hz, were measured via an LCR measurement system. All-important electrical parameters were calculated from experimental measurements of capacitance and dissipation factor at ambient temperature. Frequency-dependent of, the above-cited parameters are presented.

In situ Polymerization of Polyaniline/Samarium Oxide - Anatase Titanium Dioxide (PANI/Sm2O3-TiO2) Nanocomposite: Structure, Thermal and Dielectric Constant Supercapacitor Application Study.

Pure and varying weigh ratio of Sm2O3-TiO2 modified polyaniline nanocomposite has been successfully synthesized using in situ polymerization of aniline solution with Sm2O3-TiO2 binary oxide. The nanocomposite have been characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), X-photoelectron microscopy (XPS), Field emission-scanning electron microscope (FE-SEM), transmission electron microscopy (TEM) thermogravimetric analysis (TGA) and LCR meter. The XRD results show synthesis anatase TiO2 phase with tetragonal structure and (monoclinic and cubic) mixture structure of Sm2O3. The FE-SEM and TEM measurements appear preparing spherical nanoparticles that covered fiber morphology of polyaniline and successfully in situ polymerization process. The TGA measurements are obtain high thermal stability for polyaniline after incorporation by Sm2O3-TiO2 binary oxide nanoparticles. LCR measurement is obtained that the DC conductivity, dielectric constant and dielectric loss of nanocomposite is larger than pure polyaniline and the electric properties increase with increasing the concentration of nanoparticles.

Reduction, structures, and electrical properties of multi-layer reduced graphene oxide papers by natural sedimentation

Reduced graphene oxide (RGO) papers are extensively applied in gas sensors, electronic devices, and electromagnetic shielding. However, the structures and electrical properties for RGO papers are hard to precisely fabricate and evaluate. We developed an effective method to prepare the multi-layer RGO papers by interfacial self-assembly and natural sedimentation. The thermal structural evolutions have been elaborately measured by thermogravimetric and differential scanning calorimetry (TG-DSC) analysis, X-ray diffraction (XRD) and FT-IR spectra. Consequently, the electric properties, such as conductivity, dielectric constants, and impedance, were investigated by direct LCR measurement. We think these RGO papers would be very valuable in electromagnetic interference (EMI) shielding, heat-protective materials, and flexible electrodes.

Effects of scandium oxide on domain structure, dielectric and ferroelectric properties of barium zirconate titanate ceramics

The Sc2O3 doped Ba(Zr0.1Ti0.9)O3 ferroelectric ceramics were fabricated by the conventional solid state reaction method. The influences of Sc2O3 on their microstructure, especially domain structure, dielectric and ferroelectric properties were investigated by X-ray diffractometer, scanning electron microscope, LCR measurement system and ferroelectric tester. The Sc2O3 doped Ba(Zr0.1Ti0.9)O3 ceramics are tetragonal perovskites with no impurity phases. The average grain size of Ba(Zr0.1Ti0.9)O3 ceramics decreases from ~40 µm to ~5 µm as the Sc2O3 content increases. Both the 90° ferroelectric domains and the 180° ones exist in the 0.2 mol% Sc2O3 doped Ba(Zr0.1Ti0.9)O3 ceramics with an average grain size of ~26 µm. The ferroelectric -paraelectric phase transition temperature and the dielectric permittivity maximum of Ba(Zr0.1Ti0.9)O3 ceramics decrease with increasing Sc2O3 doping content, while the temperature stability of relative dielectric constant is improved effectively after Sc2O3 modification in BZT ceramics. The remnant polarization and the coercive field of BZT ceramics decrease in Sc2O3 highly doped BZT ceramics as the Sc2O3 content increases.

Evaluation of structural, optical, dielectric, electrical, and magnetic properties of Ce3+ doped Cu0.5Cd0.25Co0.25Fe2-xO4 spinel nano-ferrites

Rare earth cerium (Ce3+) doped Cu0.5Cd0.25Co0.25CexFe2-x O4 (x = 0, 0.0125, 0.025, 0.0375, 0.05) spinel ferrites nanoparticles were synthesized via co-precipitation technique. XRD, FT-IR, UV-VIS, VSM, LCR and current-voltage measurement techniques were utilized to investigate the structural parameters, metal stretching vibrations, indirect energy band gap, magnetic parameters and electrical behavior of synthesized ferrite powders respectively. The XRD patterns confirmed the remarkable reduction in crystallites size, cell volume and lattice constant while both densities (ρx,ρbulk) tends to increase with rise in Ce3+contents(x). The indirect energy band gaps (Eg) and the DC electrical resistivities were found in decreasing order from 3.48 to 2.50 eV and 9.902×107 to 0.142×107(ohm-cm) respectively at room temperature (303 K) with Ce3+ doping concentration. LCR meter inveterate that the dielectric constant had declining, and ac conductivity had growing trend at fix value of cerium concentration with rise of frequency from 8 Hz to 8 MHz. The soft magnetic properties can be significantly improved by the small amount of Ce3+ ion doping (x = 0.0375) with an increase of the saturation magnetization (Ms), and retentivity (Mr).

The effects of solution pH on structural, optical and electrical properties of KTiOPO4(KTP) nanoparticles synthesized by hydrothermal method

Abstract KTiOPO4 nanoparticles were synthesized by the hydrothermal method. The effects of solution pH on size, its distribution, structural, optical, dielectric, and morphological properties of products were investigated. The obtained nanoparticles were characterized by XRD, FT-IR, FE-SEM, TEM, UV–Vis analyses, and LCR measurement. The pH of the solution varied from 3.5 to 7.00. Only solution pH equal to 4.5 and 5.5 resulted in pure KTP nanoparticles. Smallest and biggest grain sizes were found to be 27.72 nm and 92.4 nm, respectively. Obtained KTP nanoparticles at pH = 5.5 showed the dielectric constant (1.68 × 104) with 3.36 times higher than that value for KTP single crystal (0.5 × 104). The best structural quality and the best optical properties were observed in this solution pH. Solution pH variation resulted in crystal lattice rotation of obtained KTP nanoparticles.

Tuning the magnetic properties of electrochemically deposited Cu2O thin films by Fe incorporation

Pristine and Fe incorporated cuprous oxide Cu2−xFexO (x = 0–3 mM) thin films were deposited on the Fluorine doped Tin Oxide (FTO) glass substrate by employing electrochemical deposition technique in an aqueous solution containing CuSO4 and FeSO4 sources. The deposited thin films were characterized with the help of X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Photoluminescence (PL), UV–Vis-NIR Spectroscopy, LCR Measurement and Vibrating Sample Magnetometer (VSM) to investigate the structural, morphological, optical, electrical and magnetic properties respectively. XRD patterns confirm about the presence of pristine and Fe incorporated Cu2O films which are in cubic structure and are grown along with their (111) preferential growth orientation. SEM images display that a three sided pyramid shaped morphology of the Cu2O thin films have significantly got changed with an increase in Fe concentrations. Photoluminescence (PL) spectra show a near band edge emission around 495 nm which are in good agreement with optical band gap of UV–Vis spectra. Temperature dependent LCR measurements illustrate that the conductivity of film decreases with an increase in the Fe dopant concentration. Vibrating Sample Magnetometer (VSM) measurement enables in understanding that the diamagnetic nature of pristine Cu2O thin film gets obviously transformed into ferromagnetic nature as the Fe concentration gets increased from 0 to 3 mM. XPS spectra enables in knowing that the 3 mM Fe doped Cu2O thin films exhibit Fe3+ ions which are substituted in Cu2O lattice.

Influence of bath temperatures on physical and electrical properties of potentiostatically deposited Cu2O thin films for heterojunction solar cell applications

In the present work, the influence of bath temperatures on structural, morphological, vibrational, optical, electrical and photo response properties of the electrochemically deposited cuprous oxide (Cu2O) thin films on fluorine doped tin oxide substrate is extensively investigated with the help of X-ray diffraction (XRD), scanning electron microscopy (SEM), Micro Raman spectroscopy, photo luminescence (PL) spectroscopy, UV–visible spectroscopy, LCR measurement, Keithley 4200 semiconductor characterization system respectively. XRD patterns reveal that the deposited Cu2O films have cubic structure grown along the preferential (111) orientation and the film deposited at 40 °C shows better crystalline nature when compared at 55 and 70 °C. The micro structural properties of films such as crystallite size (D), dislocation density (δ), micro strain (e) and stacking fault probability (α) were calculated and discussed in detail. SEM displays a well-defined three side pyramid shaped morphology for the film deposited at 40 °C. Micro Raman and PL spectra reveal the film deposited at 40 °C by being better crystalline at a higher acceptor concentration. UV–Visible study shows that the optical energy band gap increases from 2.05 to 2.17 eV with an increase in bath temperature from 40 to 70 °C. The frequency-temperature dependence of impedance analysis shows a higher electrical conductivity for a film deposited at 40 °C compared to other bath temperatures. I-V measurement illustrates a good photoconductivity response for Cu2O thin film deposited at 40 °C compared to films deposited at 55 and 70 °C.

Control of Dielectric Constant and Anti-Bacterial Activity of PVA-PEG/x-SnO2 Nanofiber

Research in the utilization of organic natural materials for electronic devices and for the biological application becoming extensively studied. We report a comprehensive review of the role of SnO2 nanoparticle and the effect of light intensity on toxicity properties, antibacterial activity, microstructure and electrical properties of PVA-PEG nanofiber films. The PVA-PEG/SnO2 nanofiber structure has been successfully fabricated on the ITO-glass substrate. Characterization was performed on samples using FTIR, XRD, SEM, toxicity and antibacterial tests, as well as LCR measurement. The presence of various light intensities has also measured the dielectric constant. The addition of SnO2 nanoparticle influenced the structure of the PVA-PEG/SnO2 nanofiber bonding functional group indicated by the appearance of Sn-O-Sn peaks at 648.08 cm-1 and 958 cm-1 wavenumbers. The addition of SnO2 nanoparticles affects the grain size of SnO2. Addition of SnO2 nanoparticles increases the detected toxicity voltage but is still below the threshold. It means the compound is not toxic, or safe to use in the body. The film lacks the antibacterial power of S. Aurelius. The addition of nanoparticles SnO2 increases the dielectric constant but decreases with increasing frequency of input voltage and the intensity of light employed to PVA-PEG/SnO2 nanofiber. The application of the light intensity reduces the dielectric constant of the PVA-PEG/SnO2 nanofiber in all nanoparticle doping ranges.

Trends in the Polish Banking System's Liquidity Risk Measured by Basel III Standards

Basel III liquidity proposals are still work in progress as new versions of regulations appear, but general shape of two major new liquidity ratios (short term LCR – liquidity coverage ratio and medium-term NSFR – stable funding ratio) seems to be established. In the paper LCR and NSFR measurement in time is proposed to assess changes in systemic liquidity risk in Poland.Estimations of two Basel ratios for years 1996-2012, based on the data on aggregate banking system from National Bank of Poland, reveal that both ratios gradually deteriorated throughout most of this period. The ratios stabilized in 2008 – probably a combined result of banks' reaction to financial crisis abroad and new regulations. It seems that on average Polish banks can meet Basel's liquidity requirement. However, reverse stress test for LCR uncovers that currently an average Polish bank would withstand a run-off of no more than 20% retail deposits – while fifteen years earlier similar stress test would show that banks were able to endure even 60% run-off rate. Also, net cash capital surplus present in the system at the beginning of the analysed period has practically disappeared, even if favourable Basel weights for mortgage loans are taken into account.

608 SUS304 切欠き材の LCR 計測

608 SUS304 切欠き材の LCR 計測

Microcontroller based LCR meter

A microcontroller based scheme for LCR measurement is described. The unknown element (an inductor or a capacitor or a resistor) is measured employing a non conventional ac bridge. The element to be measured forms one arm (side) of the bridge and the second (series) arm is made up of a simple resistor. A Multiplier type Digital to Analog Converter (MDAC), controlled by a microcontroller, serves as the other two arms. The microcontroller, after obtaining quadrature condition between the bridge output and one of the designated bridge voltages, acquires the current through and voltage across the series connected resistor. With these values and the value of digital input to the MDAC, the parameters of L or C or R values are evaluated by the microcontroller and displayed in appropriate display fields. The scheme was implemented using an Intel 8751 microcontroller. An overall accuracy of the order of ± 1.0% was achieved for the prototype with a 12-bit MDAC having an accuracy of ± 0.2%.