Frequency Dependence Of Conductivity Research Articles

The Influence of Fe Doping Tail in Unintentionally Doped GaN Layer on DC and RF Performance of AlGaN/GaN HEMTs

In this work, the performance of AlGaN/ gallium nitride (GaN) high-electron mobility transistors (HEMTs) with different Fe doping tails was systematically investigated and compared. It is illustrated that the combination of the unintentionally doped (UID) GaN layer and a thinner Fe doping buffer layer would result in a faster slope rate of Fe concentration in the UID GaN layer. The devices with the fastest slope rate of Fe concentration in the UID GaN layer exhibited excellent large signal performance, including the saturated power density ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${P}_{sat}$ </tex-math></inline-formula> ) of 9 W/mm and the power-added efficiency (PAE) of 65.6%. In addition, the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${P}_{sat}$ </tex-math></inline-formula> and the PAE of the device with the fastest slope rate of Fe concentration in UID GaN layer are 27.7% and 14.7%, which are higher than that of the device with the slowest slope rate of Fe concentration under the class AB operation conditions. Pulse <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}$ </tex-math></inline-formula> ,– <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}$ </tex-math></inline-formula> measurement results demonstrated that the buffer-related current collapse was more effectively suppressed in the 0.5- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> Fe doping buffer layer because of faster slope rate of Fe concentration in UID GaN layer. Moreover, the frequency-dependent capacitance and conductance measurement results indicated that the current collapse was relevant to deep traps in the UID GaN layer introduced by Fe doping. By reducing the concentration of the deep traps caused by Fe doping, the device showed excellent characteristics of dc and RF. Furthermore, controlling the Fe doping tail was important for designing the GaN-based power amplifier with high <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${P}_{sat}$ </tex-math></inline-formula> and PAE.

Dielectric relaxation and scaling of AC conductivity observed in mixed valence perovskite Eu2CoMnO6

Monophasic and polycrystalline double perovskite Eu2CoMnO6 has been synthesized, and its structural characterization, frequency and temperature-dependent dielectric relaxation have been studied. Observed thermally activated dielectric relaxation was explained using the empirical Havriliak–Negami (HN) dielectric relaxation function with an estimated activation energy [Formula: see text] [Formula: see text] 0.22 eV and attempt frequency [Formula: see text] [Formula: see text] 2.46 × 109 Hz. The frequency-dependent AC conductivity data, over a wide range of temperature (100–325 K), followed the empirical universal power law behavior ([Formula: see text], [Formula: see text] is the constant exponent) showing two different frequency exponents, respectively, in the high- and low-temperature regions. The high-temperature ([Formula: see text] 275 K) conductivity data followed the continuous time random walk (CTRW) approximation model proposed by Dyre. However, this model failed to reproduce the observed conductivity spectra in the low-temperature side ([Formula: see text] 200 K). Interestingly, both the high- and low-temperatures’ conductivity data can be scaled to the master curve with suitably chosen scaling parameters.

Monitoring the pozzolanic effect of fly ash in blended OPC mortars by electrical impedance spectroscopy

Fly ash (FA) is a pozzolanic material widely used to replace ordinary Portland cement (OPC) in mortars and concretes. The main purpose of this replacement is to improve the durability of these materials in a sustainable way from an environmental and economical perspective.Main technical advantages, such as the improvement in durability and the enhancement of mechanical properties with long-time hydration, are derived from the pozzolanic activity. Several studies aimed to evaluate the pozzolanic reaction extent have been reported by using thermogravimetric analysis (TGA), mechanical compressive strength and mercury intrusion porosimetry (MIP). Besides, other complementary non-destructive techniques that reflect the effect of FA on microstructure are of great scientific and technical interest.In this work, an alternative non-destructive method, the electrical impedance spectroscopy (EIS) followed by the equivalent circuit (EC) analysis has been applied to identify two electrical relaxations, which are strongly associated to microstructural properties.The high frequency relaxation was assigned to the electrical conductivity of the calcium silicate hydrate (C-S-H) gel. Additionally, this C-S-H gel conductivity was separated into dc-conductivity and frequency-dependent conductivity, that provided information regarding the periods of early pozzolanic reaction (around 12 days) and high pozzolanic activity (around 28 days).This research provides conclusive evidence of the validity of the applied EIS-EC method on account of the significative relationships found between electrical parameters and physicochemical properties determined by TGA, compressive strength and MIP.Specifically, non-evaporable water, compressive strength and gel-pore-volume of diameter less than 10 nm exhibited significative exponential correlations with dc-electrical resistivity of the high frequency relaxation. These correlations validated the appropriate allocation of the high frequency relaxation to C-S-H gel.

Enhanced multiferroics properties of strontium substituted bismuth ferrite prepared by auto combustion method

A low cost and simple auto combustion method was used to prepare the Bi1-xSrxFeO3 (x=0.0, 0.04, 0.08, 0.12, 0.16) multiferroics samples. X-ray diffraction patterns confirms the integration of BFO pure phase nanoparticles with a perovskite structure of ABO3 type having space group R3c. Spherical structure with little agglomeration was observed during the morphological studies of the prepared samples. Sr2+ substituted at the A-site produces expansion in Raman modes and increased variations in cation site occupancy. Impedance analyzer was used to examine the frequency dependent dielectric parameters (ε´, tanδ), electric conductivity (σac), impedance (Z) and electric modulus (Mʹ and M″) of the samples in frequency between 20 Hz and 20 MHz). Maximum value of dielectric constant was observed at very low frequency for x=0.0 samples and it decreases by increasing concentration. Resonance peak was observed in tangent loss for high content of strontium. Maximum value of Impedance was observed at low frequency and it decreases by increasing frequency which is due to the grain and grain boundary contributions. It is observed that ac conductivity of the samples is found to be frequency dependent and it varies with doping of Sr in BFO. Improved polarization was examined in P-E loop of Sr doped BFO nanoparticles.

Comparative study of the effect of different interlayer thicknesses on frequency dependent electric modulus and conductivity in Au/n-Si structures

Frequency dependent capacitance (C) and conductance (G/ω) data for Au/n-Si structures fabricated at room temperature without interlayers and with 5 nm and 10 nm aluminium-oxide (Al2O3) interlayer thicknesses are investigated. The Al2O3 interlayers were deposited by atomic layer deposition. Data on the complex electric modulus (M*) and alternating current electrical conductivity (σac) values are acquired for the three structures in the 3 kHz-3 MHz frequency range between (-3 V) – (+5 V) bias interval and compared. It was observed that the C and G/ω values decreased with the increase in frequency and interlayer thickness and that the frequency increases as a result of polarization which also increases M*, especially in 5 nm and 10 nm interlayered structures. Frequency and interlayer thickness increment have a positive impact by increasing σac, while conductivity has been shown to be highly sensitive to the presence of an interlayer and to its thickness.

Temperature dependent electrical transport behavior of (100-x)Bi2O3-x(BaTiO3) glass system

Impedance measurements were performed as a function of temperature (RT to 700 K) in the frequency range (1 Hz-1MHz) on fabricated Bismuth Barium Titanate glass samples. Dielectric permittivity is found to be increased on increasing both the temperature and BaTiO3 (BT) content in highly polarizable glass matrix of Bi2O3. Experimental data obtained for imaginary part of electric modulus (M″)has been fitted theoretically using non-exponential Kohlrausch-Williams-Watts (KWW) function, however Jonscher's universal power law has been employed to analyze the frequency dependent ac conductivity. The calculated activation energy values for both the samples have been found to be in close agreement with each other and qualify for doubly ionized oxygen vacancies, proposing that the similar kind of charge carriers are involved in the relaxation and conduction mechanisms. Stretched exponent (β) of Modulus and power exponent (n) of ac conductivity, estimated from theoretical fitting of experimental data, have been found to be dependent on temperature and BT (BaTiO3) content. On increasing temperature, an increase in values of (n) suggests that non-overlapping small polaron tunneling (NSPT) model can be easily applied to explain ac conduction and hopping transport mechanisms of the fabricated glass samples.

Effect of processing temperature on structural, optical and frequency dependent electrical responses of solid-state sintered bismuth sodium titanate

A facile way to control the functional properties of pure Bi0.5Na0.5TiO3 (BNT) could be of great significance when it comes to manufacturing and application of Pb free dielectrics. Herein, a stark modulation in optical, dielectric and conductivity responses of pure BNT with morphological and crystallographic modifications brought about simply by changing the processing temperature (850 ≤ Tsint≤ 1150 °C) along with a detailed correlation between the functional and structural properties has been reported, which are yet to be addressed in detail for BNT in particular. Industrially, the solid state reaction (SSR) route being the most viable mass production technique was adopted in this study. A conspicuous change in crystallographic distortion along with microstructural development was rendered by increasing Tsint without generating any 2nd phase. A noticeable modulation in direct-mode optical transition energy enabled by morphology dependent size confinement effect with increase in Tsint makes BNT based compositions a potential candidate for photochemical application. An optimum Tsint corresponding to peak εr' for pure BNT was established and a technologically desired frequency-stable εr' plateau with low loss was observed to extend remarkably from over 1 MHz to below 0.1 kHz as Tsint reaches 1150 °C, in which both temperature dependent structure and morphology played a decisive role. Distinct frequency dependent conductivity zones were also identified for pure BNT under different measurement and processing temperatures, which were also in direct congruence with the dielectric responses.

Theory of plasmonic edge states in chiral bilayer systems

We analytically describe the plasmonic edge modes for an interface that involves the twisted bilayer graphene (TBG) or other similar Moire van der Waals heterostructure. For this purpose, we employ a spatially homogeneous, isotropic and frequency-dependent tensor conductivity which in principle accounts for electronic and electrostatic interlayer couplings. We predict that the edge mode dispersion relation explicitly depends on the chiral response even in the nonretarded limit, in contrast to the collective bulk plasmonic excitations in the TBG. We obtain a universal function for the dispersion of the optical edge plasmon in the paramagnetic regime. This implies a correspondence of the chiral-TBG optical plasmon to a magnetoplasmon of a single sheet, and chirality is interpreted as an effective magnetic field. The chirality also opens up the possibility of nearly undamped acoustic modes in the paramagnetic regime. Our results may guide future near-field nanoscopy for van der Waals heterostructures. In our analysis, we retain the long-range electrostatic interaction, and apply the Wiener-Hopf method to a system of integral equations for the scalar potentials of the two layers.

Transient Analysis of Multiphase Transmission Lines Located above Frequency-Dependent Soils

This paper evaluates the influence of frequency-dependent soil conductivity and permittivity in the transient responses of single- and double-circuit transmission lines including the ground wires subjected to lightning strikes. We use Nakagawa’s approach to compute the ground-return impedance and admittance matrices where the frequency-dependent soil is modeled using Alípio and Visacro’s model. We compare some elements of these matrices with those calculated by Carson’s approach which assumes the frequency constant. Results show that a significant difference can be obtained in high resistive soils for these elements in impedance and admittance matrices. Then, we compute the transient responses for single- and double-circuit lines with ground wires located above soils of 500, 1000, 5000, and 10,000 Ω·m considering the frequency constant and frequency-dependent parameters generated for two lightning strikes (subsequent stroke and Gaussian pulse). We demonstrate that the inclusion of frequency dependence of soil results in an expressive reduction of approximately 26.15% and 42.75% in the generated voltage peaks in single- and double-circuit lines located above a high-resistive soil. These results show the impact of the frequency-dependent soils that must be considered for a precise transient analysis in power systems.

Effects of cobalt doping on structural, optical, electrical and electrochemical properties of Li4Ti5O12 anode

Cobalt-doped Li4Ti5O12 (LTO) i.e Li4Ti5−xCoxO12 (x = 0, 0.05, 0.1, 0.15, 0.2) powders have been synthesized by solid state reactions and examined for effects of Cobalt (Co) concentration on structural, optical, electrical and electrochemical properties of LTO. X-ray diffraction (XRD), Raman spectroscopy and field-emission scanning electron microscopy (FESEM) evaluate phase composition and morphology of samples. Optical study reveals reduction in bandgap Eg of LTO from 3.4 to 2.7 eV for x = 0.15, with Eg extension into visible region around 515–740 nm due to increased conduction electrons and energy levels from 3d7 orbitals of Co and induced oxygen vacancies. Electronic conductivity of sample with x = 0.15 increases by 104 as compared to LTO due to conversion of Ti4+ to Ti3+ ions and increased Ti4+-Vo-Ti3+ hopping centers. Ionic conductivity and diffusivity increase upto 2.0×10−7Scm−1 and 4.6×10−12cm2s−1 for x = 0.15, owing to increased lattice spacing by substitution of Ti4+ with Co2+. Frequency dependent conductivity suggests hopping of Li+ ions as dominant conduction in LTO. Thermally activated Li+ ions follow different conduction mechanisms in different temperature regimes. Low activation energies Ea of 0.3–0.5 eV indicate conduction of ions through interstitial pathways i.e 8a-16c-8a. High Ea of 0.7–1.15 eV suggest hopping of ions through vacancy/defect mediated channels or other long routes. Electrochemical tests demonstrate unexpected degradation in electrochemical performance for dilute dopant concentration; x = 0.05 and 0.1, as compared to LTO, which is attributed to substitution of Co2+ ions at Li+ tetrahedral (8a) sites. However, for x = 0.15 electrochemical activity gets better indicating substitution of more of Co2+ ions at Ti4+ octahedral sites.

Strange Metals as Ersatz Fermi Liquids.

A long-standing mystery of fundamental importance in correlated electron physics is to understand strange non-Fermi liquid metals that are seen in diverse quantum materials. A striking experimental feature of these metals is a resistivity that is linear in temperature (T). In this Letter we ask what it takes to obtain such non-Fermi liquid physics down to zero temperature in a translation invariant metal. If in addition the full frequency (ω) dependent conductivity satisfies ω/T scaling, we argue that the T-linear resistivity must come from the intrinsic physics of the low energy fixed point. Combining with earlier arguments that compressible translation invariant metals are "ersatz Fermi liquids" with an infinite number of emergent conserved quantities, we obtain powerful and practical conclusions. We show that there is necessarily a diverging susceptibility for an operator that is odd under inversion and time reversal symmetries, and has zero crystal momentum. We discuss a few other experimental consequences of our arguments, as well as potential loopholes, which necessarily imply other exotic phenomena.

Long range electromagnetic field nature of nerve signal propagation in myelinated axons

The nature of saltatory conduction in myelinated axon described by equivalent circuit and circuit theory is still contentious. Recent experimental observations of action potentials transmitting through disjointed nerve fibers strongly suggest an electromagnetic wave propagation mechanism of the nerve signals. In this paper, we employ the electromagnetic wave model of the myelinated axon to describe action potential signal propagation. We use the experimental frequency-dependent conductivity and permittivity values of the nerve tissues in order to reliably calculate the electromagnetic modes by using electromagnetic mode solvers. We find that the electromagnetic waves above 10 kHz can be well confined in extracellular fluid–myelin sheath–intracellular fluid waveguide and propagate a distance of 7 mm without much attenuation. Our study may serve as one of the fundamental researches for the better understanding of the nervous system.

Superconductinglike response in a driven gapped bosonic system

We propose a novel mechanism for the photo-induced superconducting-like response recently reported in cuprates and other strongly correlated materials. This mechanism relies on quantum-fluctuating bosons consisting of electron pairs. With periodic drive, the electron pairs and vacancies of pairs form a coherent non-equilibrium condensate, different from conventional superconductors, yet showing superconducting-like response in some regimes even with dissipation. Unlike the case of driven fermionic bands which results in the familiar Floquet bands with hybridization gaps, for driven bosons the "gap" opens up in the momentum direction, resulting in a resonant region in momentum space where the eigenvalues are complex. We give a simple physical argument why this picture leads to a "perfect conductor" which exhibits superconducting-like frequency-dependent conductivity but no Meissner response. While our model is quite general, in the case of cuprates, quantum-fluctuating pair density wave in the pseudogap region may serve as the origin of the quantum-fluctuating electron pairs.

Impedance and Electric Modulus Spectroscopy of Polycrystalline La0.5Sr0.5Bi0.2Co0.4Fe0.4O3–d Cathode Ceramic for Intermediate Temperature SOFCs

In the present research work, La 0.5 Sr 0.5 Bi 0.2 Co 0 . 4 Fe 0.4 O 3– d cathode ceramic powder is synthesized through cost-effective flash pyrolysis process and further conventional heat treatment for sintering for IT-SOFCs. The crystal structure, unit cell parameters and bond length are determined by using the Rietveld refinement program. The XRD result indicates existence of a pure single phase with R C space group symmetry detected from the sample which has been sintered at 700 ℃. SEM images of fracture surface of sample sintered at 700 ℃ showed a high porosity and nano grain sizes (50-100 nm). Impedance and electric modulus spectroscopic methods are used to identify the relaxation phenomena in La 0.5 Sr 0.5 Bi 0.2 Co 0 . 4 Fe 0.4 O 3– d ceramic over a broad range of temperature and frequency. A single relaxation peak is observed in the imaginary part of impedance and electric modulus spectra, which could be due to the contribution of grain boundary of La 0.5 Sr 0.5 Bi 0.2 Co 0 . 4 Fe 0.4 O 3– d ceramic. The imaginary part of modulus ( ) spectra is analyzed with help of non-exponential decay function or Kohlrausch–Williams–Watts (KWW) parameter ( β ). In the combined plot of the imaginary part of impedance and electric modulus spectra at 210 ℃, only a single peak of and is observed at the same frequency which indicates that the conduction process is a long-range motion of the charge carriers. The frequency-dependent conductivity is followed by the Jonscher’s double power law in the temperature range 30-210 ℃.

Terahertz Charge Carrier Mobility in 1D and 2D Semiconductor Nanoparticles.

We investigate the charge carrier mobility in 1D and 2D semiconductor nanoparticle domains with a focus on the interpretation of THz mobility measurements. We provide a microscopic understanding of the frequency-dependent charge carrier transport in these structures of finite lateral size. Yet unexplored oscillations in the frequency-dependent complex conductivity and a strong size dependence of the mobility are observed. The quantum nature of the charge carrier states results in oscillations in the frequency-dependent mobility for subresonant THz probing, seen in experiments. The effect is based on the lack of an energy continuum for the charge motion. In 2D systems the mobility is further governed by transitions in the two orthogonal x- and y-directions and depends nontrivially on the THz polarization, as well as the quantum well lateral aspect ratio, defining the energetic detuning of the lowest THz-photon transitions in both directions. We analyze the frequency, length, and effective mass dependencies.

Monte Carlo method with Bézier curves for the complex conductivity of curved CNT-polymer nanocomposites

Monte Carlo (MC) method is often adopted to calculate the DC conductivity of nanocomposites with straight-line carbon nanotubes (CNT), but calculations for the frequency-dependent AC conductivity and dielectric properties with curved CNTs are rare. The difficulties lie in the geometrical modeling of curved CNTs and the determination of electric potentials for thousands of CNTs and thousands of random points on the coated surface around each CNT. In this paper, a three-dimensional curved CNT network is established based on random third-order Bézier curves. By calculating the distance between the curves through a culling approach, the MC method is developed to calculate the complex conductivity under an AC field. Curved CNTs were divided into three groups according to the maximum curvature and compared with straight-line CNTs. The results show that both conductivity and dielectric constant can notably decrease with the bending degree of Bézier curves, and the percolation threshold can increase by about 20% as compared to that with straight-line CNTs. The frequency effects of complex conductivity are also assessed, and found to depend on the diameter of CNTs, barrier height, and the complex conductivity of polymer matrix as well. Several other new features of the theory are also highlighted.

AC conductivity and correlation effects in nano-granular Pt/C

Nano-granular metals are materials that fall into the general class of granular electronic systems in which the interplay of electronic correlations, disorder and finite size effects can be studied. The charge transport in nano-granular metals is dominated by thermally-assisted, sequential and correlated tunneling over a temperature-dependent number of metallic grains. Here we study the frequency-dependent conductivity (AC conductivity) of nano-granular Platinum with Pt nano-grains embedded into amorphous carbon (C). We focus on the transport regime on the insulating side of the insulator metal transition reflected by a set of samples covering a range of tunnel-coupling strengths. In this transport regime polarization contributions to the AC conductivity are small and correlation effects in the transport of free charges are expected to be particularly pronounced. We find a universal behavior in the frequency dependence that can be traced back to the temperature-dependent zero-frequency conductivity (DC conductivity) of Pt/C within a simple lumped-circuit analysis. Our results are in contradistinction to previous work on nano-granular Pd/hbox {ZrO}_2 in the very weak coupling regime where polarization contributions to the AC conductivity dominated. We describe possible future applications of nano-granular metals in proximity impedance spectroscopy of dielectric materials.

Effect of ionic liquid on structural, thermal and electrical transport properties of PVA-PVP based polymer blend electrolyte membrane

The present paper deals with the loading effect of ionic liquid (IL), 1-ethyl-3-methylimidazolium methylsulfate [EMIM][MS] on structural and electrical transport properties of polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), polyethylene glycol (PEG)- salt, sodium methyl sulfate (MeSO4Na) based polymer blend electrolyte (PBE) films. The samples were prepared using conventional solution cast method. The x-ray Diffraction (XRD) result shows that PBE films has characteristic peak with broad halo appeared in the range 2θ = 19.95° to 22.72° reveals the amorphous nature (semi-crystalline).The % degree of crystalinity (X c ) of prepared IL based PBE films were found to decreases with increasing IL content. Fourier transform infrared (FTIR) in total attenuated reflectance (ATR) mode analysis reveals the interaction between the functional groups (C=O and O–H) of polymer electrolyte with the cation, EMIM+/anion of IL/salt. Thermogravimetric analysis (TGA) shows that IL based PBE samples decomposes in multistep and Td,onset/peak value decreases with IL loading. Sample containing 30 wt%IL shows optimum dc conductivity value ∼1.5 × 10−4 S cm−1 at 30 °C with minimum activation energy ∼0.21 eV. Logσ versus 1000/T plot for all PBE sample follow the Arrhenius type thermally activated process and activation energy decreased with increasing IL content in PBE films. Frequency dependent conductivity behavior for IL based PBE film follow the Jonscher’s power law with power law exponent, n value<1 (amorphous polymeric system). AC conductivity spectra and loss tangent spectra (tanδ) with respect to IL/temperature content scalled successfully. Dielectric relaxation behavior and conductivity relaxation were analyses with respect to IL content and temperature. Mobility, total number of charge/ion density, ion diffusivity was estimated. Ionic transference number (ITN) measurement (tion ∼0.98, tele ∼0.02) reveals that ions are principal charge carriers in present system. Linear sweep voltametry (LSV) and cyclic voltamerty (CV) measurements show that 30 wt%IL containing sample has electrochemical stability window (ESW) ∼±2.7volt and Faradic oxidation reduction peaks were observed, respectively.

On the frequency-dependent complex-dielectric, complex-electric modulus and conductivity in Au/(NiS:PVP)/n-Si structures

On the frequency-dependent complex-dielectric, complex-electric modulus and conductivity in Au/(NiS:PVP)/n-Si structures

High thermal stability of the YNbO4 − CaYTiNbO7 composites for radio frequency and microwave applications

The present work shows present the dielectric properties of YNO – CYNTO ceramic composites at Radio Frequency (RF) and Microwave (MW) regions. X-ray diffraction showed that the addition of CaTiO3 (CTO) on YNbO4 (YNO) caused the formation of the CaYTiNbO7 (CYNTO) phase. In the RF analysis, a typical universal dielectric response in the frequency of the temperature-dependent conductivity was found; the frequency-dependent AC conductivity at different temperatures indicates that the conduction process is thermally activated. Regarding the values of the temperature coefficient of capacitance (TCC) was observed a change of signal with the increment of CTO. Besides, the activation energies of composites were calculated and demonstrated an increase with addition of the CTO. In the MW range, it was observed that permittivity and dielectric loss enhance with the addition of CTO. Moreover, the addition caused the improvement of the thermal-stability of YNO where τf value for YCT5% was equal to +0.64 ppm.°C−1. The composites were analyzed as antennas presenting a reflection coefficient below - 10 dB at the resonant frequency, realized gain of 5.10–5.45 dBi, bandwidth of 129–355 MHz and radiation efficiency above 95%. The results obtained indicate that YNO – CYNTO system would be interesting candidates in microwave operating devices.