Electric Modulus Formalism Research Articles

Relaxation dynamics and conductivity in poly(vinylidene fluoride)/graphene oxide composites

The αc relaxation, which originates from the crystalline phase of Poly(vinylidene fluoride), is studied in the composite system of Poly(vinylidene fluoride) and Graphene oxide. PVDF/GO composites were prepared using solvent casting. The crystalline phases in PVDF/GO composites were identified using XRD and quantified using FTIR. The thermal properties were analyzed using DSC, and the crystallization degrees were calculated. The electric modulus formalism is employed to understand the relaxation mechanism with temperature. AC conductivity studies reveal the activation energy for conduction in these composites.

Short and long range ordering on dielectric relaxation of AgI doped glass-ceramic

The dielectric relaxation process of an amorphous glassy system, AgI - CdO -V2O5 -P2O5 - ZnO has been reported here. Electric modulus formalism has been carried out to explore the dielectric behavior of the as-prepared samples and the experimental results have been analyzed in the light of some theoretical models. Study of the nature of peak separation between imaginary components of electric modulus and the complex impedance plots reveals that the present system with lower AgI content should have a tendency to exhibit long range order for the relaxation of charge carriers. On the other hand, the present system with higher AgI content exhibits a relaxation process, dominated by short range order of charge carriers. This relaxation process is found to be Debye type for AgI doping up to x = 0.20 and it becomes non-Debye type beyond that composition range.

Dielectric Characterization of Solutions of Galactomannan Extracted from Adenanthera pavonina L.: Effects of Purification and Ethanol Concentration.

Galactomannans are polysaccharides obtained from legume seed extraction. They present a chemical structure consisting of D-mannose chains linked by glycosidic bonds and galactose branches. The main focus lies in their use as thickeners in the food industry, aimed at improving the dielectric properties of food during heating processes within the radiofrequency and microwave ranges. In this work, the prepared galactomannan samples were electrically analyzed through impedance spectroscopy, which is a powerful physical technique. From the experimental measurements, the dielectric permittivity and loss tangent of the galactomannan solutions were analyzed and the electrical modulus formalism was used to study the dielectric relaxations. Crude galactomannans exhibited higher values of permittivity, conductivity, and losses compared to purified galactomannans. Increasing ethanol concentration in galactomannan purification causes an increase in the permittivity and conductivity of galactomannan solutions. In a 1% solution, at 1 kHz, the permittivity increased from 378.56 to 538.09, while in the 2% solution, this increase was from 656.22 to 1103.24. Regarding the conductivity, at the same frequency, the increase was from 1.6 × 10-3 to 3.3 × 10-3 Ω-1m-1 and from 2.9 × 10-3 to 5.5 × 10-3 Ω-1m-1, respectively. The rise of the ethanol concentration in galactomannan purification led to a decrease in the relaxation time, from 448.56 to 159.15 μs and from 224.81 to 89.50 μs in the solution with 1 and 2%, respectively. The results suggest that galactomannan from Adenanthera pavonina L. has potential for use in the food industry.

Enhanced Spectroscopic Insight into Acceptor-Modified Barium Strontium Titanate Thin Films Deposited via the Sol-Gel Method.

In the present paper, composite thin films of barium strontium titanate (BaxSr1-xTiO3) with an acceptor modifier (magnesium oxide-MgO) were deposited on metal substrates (stainless steel type) using the sol-gel method. The composite thin films feature BaxSr1-xTiO3 ferroelectric solid solution as the matrix and MgO linear dielectric as the reinforcement, with MgO concentrations ranging from 1 to 5 mol%. Following thermal treatment at 650 °C, the films were analyzed for their impedance response. Experimental impedance spectra were modeled using the Kohlrausch-Williams-Watts function, revealing stretching parameters (β) in the range of approximately 0.78 to 0.89 and 0.56 to 0.90 for impedance and electric modulus formalisms, respectively. Notably, films modified with 3 mol% MgO exhibited the least stretched relaxation function. Employing the electric equivalent circuit method for data analysis, the "circle fit" analysis demonstrated an increase in capacitance from 2.97 × 10-12 F to 5.78 × 10-10 F with the incorporation of 3 mol% MgO into BST-based thin films. Further analysis based on Voigt, Maxwell, and ladder circuits revealed trends in resistance and capacitance components with varying MgO contents, suggesting non-Debye-type relaxation phenomena across all tested samples.

Dielectric Relaxation and AC Conductivity of Fe-Doped Glassy Semiconductors: Role of Fe Doping on Relaxation Time

AC conductivity and dielectric parameters are supposed to be two noticeable parameters that ensure the applicability of present samples for electronic and other applications. Presently, Fe-doped glassy semiconductors were developed by melt-quenching route and characterized using FT-IR, SEM, EDAX and decoupling index for structural, morphological and elemental examinations. Frequency dependent dielectric constant, AC conductivity, dielectric loss at different temperatures have been explored in a wide frequency and temperatures ranges. Electric modulus formalism has been conceived asit can exclude the electrode polarization effect at low frequency regime and suggest the transition from long-range mobility to short-range mobility assembly of polarons. It is also noteworthy that relaxation times are found to decrease with temperatures, which may indicate about the faster movement of charge carriers. The variation of KWW parameters directly indicate that after doping of Fe content into the resultant materials, the relaxation process is shifted from Non-Debye to Debye type up to a limit. By crossing the limiting value of composition (x = 0.3), it becomes Non-Debye type in a very slow rate. The present system also exhibits a small relaxation time in comparison with others’ works. Lower values of dielectric constant at high frequencies are expected to be important for their applications in photonics and opto-electronics. Scaling method of electric modulus spectra indicate that the dielectric relaxation process in the present system leads to a common relaxation process at various temperatures, but it is strongly dependent on compositions.

Colossal permittivity, impedance analysis and electric properties in AlGaN/GaN HEMTs

The electric and dielectric processes of AlGaN/GaN/Si HEMTs produced by molecular beam epitaxy were examined utilizing direct current-voltage, impedance spectroscopy, and DLTS measurements. Using current-voltage measurements, the DC electrical characteristics of AlGaN/GaN/Si HEMTs revealed the self-heating effect. The relaxation dynamics of charge carriers appear to be studied by the conductance mechanism and electric modulus formalisms. Behavior that is frequency dependent has been observed in impedance spectroscopy. Last but not least, DLTS data have demonstrated the existence of electron traps. The prevalence of parasitic effects and conduction mechanisms are remarkably correlated with deep levels.

Dielectric relaxation and conductivity phenomena in ferroelectric ceramics at high temperatures

The issues related to microstructure and its effects on functional properties of electroceramics become increasingly prominent with the progressive downscaling of electronics. In this study, temperature-dependent dielectric and impedance data of BaTiO3 (BT), Sr-doped BT (BST) and layer-structured BaBi4Ti4O15 (BBTO) ceramics are systematically investigated to reveal the effects of doping and perovskite layering on the dielectric relaxation and conduction processes at high temperatures. By using complex impedance spectroscopy, it is demonstrated that the ceramics are electrically heterogeneous structures displaying a non-ideal Debye-like behavior at high temperatures. Using a suitable equivalent circuit model, the impedance diagrams at different temperatures are simulated and the refined values of macroscopic resistance and capacitance are used for the identification and characterization of particular microstructural regions (grains, grain boundaries, interfaces, etc.). The approach of combining the impedance, electric modulus and permittivity formalisms is demonstrated to be effective in explaining the peculiarities of the electrical charge transport mechanism and relaxation in the grains, grain boundaries and interface layers of the ceramics.

Synthesis, characterization, electrical, and magnetic properties of polyvinyl alcohol/carboxymethyl cellulose blend doped with nickel ferrites nanoparticles for magneto‐electronic devices

AbstractSolid polymer electrolytes are an intriguing technology in terms of magneto‐opto electronic applications due to having a high dielectric constant, a small band gap, and excellent magnetic characteristics. In order to improve structural, optical, dielectric, conductivity, and magnetic characteristics, this research seeks to prepare nickel ferrite (NiFe2O4) nanoparticles and polyvinylalcohol (PVA)/carboxymethyl cellulose (CMC) films containing NiFe2O4. Nanoparticles of NiFe2O4 are prepared using the co‐precipitation method. The CMC/PVA–NiFe2O4 nanocomposites films are prepared using casting solution. To improve their structural, optical, conductivity, dielectric, and magnetic characteristics, these films electrolytes were examined using XRD, TEM, FT‐IR, UV–vis, and VSM measurements. According to the XRD analysis, the CMC/PVA blend polymer matrix demonstrates a considerable increase in amorphous nature with the NiFe2O4 nanoparticles (NPs) content, producing a highly flexible polymer backbone, increasing ionic conductivity of the CMC/PVA–NiFe2O4 nanocomposite films. The complexation of dopant cations with the CMC/PVA polymer matrix's backbone is confirmed by the FT‐IR spectroscopy. According to the UV–visible technique, the dopant NiFe2O4 concentration considerably affects the optical energy band gap, and Urbach energy of the pure CMC/PVA. At higher loading, these effects are more pronounced. At room temperature, ac conductivity, the dielectric behavior, and electrical modulus formalism were studied. The blend's highest AC conductivity is 4.77 × 103 S/cm. After increasing the loading of NiFe2O4 to 1.5 wt%, it increased to 8.07 × 104 S/cm. There has also been research on dielectric permittivity and electric modulus to further understand conductivity relaxation and charge storage qualities. The polymer nanocomposite, generally, displayed better optical, dielectric constant, conductivity, and magnetic characteristics compared to pure CMC/PVA being useable in terms of high energy storage nanoelectronics' manufacturing.Highlights NiFe2O4 nanoparticles were prepared by using the co‐precipitation method. Nanocomposite films of CMC/PVA–NiFe2O4 were successfully prepared by casting method. XRD patterns confirmed the increase in the degree amorphousity for nanocomposites films compare pure blend. From optical energy gap results for samples prepared was enhanced after addition NiFe2O4. The dielectric and magnetic properties showed that all nanocomposites films exhibited enhanced as compared to pure CMC/PVA film.

Experimental Investigation on Electric and Dielectric Properties of Thallium Ions Doped Sodium Zinc Phosphate Glass

Sodium zinc phosphate glasses modified by Tl2O addition of composition Na2−xTlxZnP2O7 (x = 0, 0.005, 0.01, and 0.015) are synthesized following the melt quenching technique. The structure of the glass samples is analyzed by the Fourier transform infrared absorption spectroscopy. The results suggest that the phosphate network is polymerized by the addition of Tl+ ions. The electrical conductivity, electric modulus, and dielectric constant characteristics of the glasses are measured over a wide continuous frequency range of 10−2 Hz–1 MHz and in the temperature range 293–473 K by the impedance spectroscopic method. The ac conductivity data are analyzed following the power law exponent (S) and the proposed correlated barrier hopping mechanism (CBH) is the most suitable conduction mechanism in the studied compositions. The electrical modulus formalism is applied to analyze the electric data to study their dielectric relaxation. Non‐Debye type relaxation is obtained. From the obtained results, the present glass can be used as a high‐energy capacitor.

Determination of dielectric performance and surface heteromorphology in single-walled carbon nanotube/vinylester polymer composites by fractal approaches

This study aims to establish a relationship between the dielectric characteristics and fractal parameters of single walled carbon nanotube reinforced vinylester based nanocomposites manufactured by sheet molding compound process. The complex dielectric permittivity was analyzed and interpreted using electric modulus formalism. The topography of both unfilled and single-walled carbon nanotube reinforced nanocomposites has been investigated using scanning electron microscopy (SEM) to provide correlation between experimental dielectric data and fractal theory. The self-similar microstructure was observed in micro photos for both materials. The superficial particle and cluster coverage ratio were calculated with the application of the scaling theory. Additionally, critical exponent and the fractal dimensions that determine the environment-area relationship have been determined by Slit Island Method (SIM) which is used to process 2-dimensional digital microscopic images. Fractal dimensions estimated with SIM were compared with the fractal dimensions computed obtained by box counting method for reliable results. It has been revealed that the surface of the composite consists of amorphous clusters with different sizes independent of each other and the structure is self-affine. In addition, the superficial area and cluster size have been shown to have a significant effect on the fractal dimension. As a result, the relationship between the dielectric permittivity of the material, determined by the electrical module formalism, and the morphological surface formation defined by the fractal analysis method and the SIM method, were determined and the results were compared with similar studies in the literature in this article.

Structural, Frequency and Temperature Dependent Dielectric Properties of Zn2+ Substituted Ni-Co Based Spinel Ferrite (ZnxNi0.8−xCo0.2Fe2O4)

Zinc substituted nickel-cobalt ferrites, i.e., ZnxNi0.8−xCo0.2Fe2O4 (x = 0.0, 0.05, 0.10 and 0.20) with average crystallite size 100 nm were synthesized by citrate-gel auto-combustion method to investigate effects of Zn2+ substitution on the structural and dielectric properties. Both X-ray diffraction (XRD) and IR spectroscopy studies confirms the formation of pure cubic spinel structure. Variation of lattice parameter infers Vegard’s law linear dependence with the addition of Zn2+ concentration. The temperature-dependent behavior of dielectric and modulus spectra has been studied within the frequency range 100 Hz-100 kHz for different temperatures between 100 K and 400 K. It was concluded that the dielectric responses of ZnxNi0.8−xCo0.2Fe2O4 are found to be frequency dependent and thermally activated. Also, In the Zn doped ferrites variations of dielectric loss (tan δ) and the imaginary part of electric modulus (M") show the presence of the non-Debye type of dielectric relaxation. Rise in Zinc concentration leads to a decrease in dielectric constant (ε r) due to the declining of Fe3+–O–M2+ conducting network (M is Co or Ni). Here, we report a low loss tangent factor of the order of for the sample Ni0.6Zn0.2Co0.2Fe2O4 make this composition suitable for high frequency-applications at room temperature. The activation energy is calculated from electric modulus formalism and DC electrical conductivity and found to increase with further substitution of Zn2+ concentration.

Investigation on electrical transport and dielectric relaxation mechanism in TbCrO3 perovskite orthochromite

Herein, the TbCrO3 (TCO) chromite was synthesized by the sol-gel auto-combustion route and sintered at 900 °C. The Rietveld analysis of the room temperature powder X-ray diffraction profile confirmed the single-phase formation of the material crystallized in the orthorhombic phase of the perovskite structure with Pbnm space group symmetry. The surface morphology, the elemental composition, and the chemical states of the compound were investigated by field emission scanning electron microscopy, energy dispersive X-ray analysis, and X-ray photoelectron spectroscopy, respectively. The electronic density of states, band structure, and electron density were analyzed by Density Functional Theory. The electrical transport and dielectric relaxation mechanism were investigated using complex impedance spectroscopy over the experimental frequency and temperature ranging from 40-1.2x106Hz and 138−273 K, respectively. Two semicircular arcs in the impedance complex plane plots were modeled to an equivalent circuit configured by RG∥QG+RGB∥QGB which were attributed to the contributions of the highly resistive grain boundaries and relatively conducting grains in the material. The electrical conductivity as a function of frequency followed Jonscher’s universal power law behavior and an increasing nature of the temperature-dependent frequency exponent suggested small polaron hopping as the electrical conduction mechanism of the material. The least capacitive response of the TCO system was investigated by the complex electrical modulus formalism and the frequency-dependent imaginary modulus spectra were modeled by the Kohlrausch–Williams–Watts function, which resolved the thermally activated peaks of bulk and interface effects to the dielectric relaxation mechanism. The dielectric constant exhibited Maxwell-Wagner interfacial polarization effects and the dielectric loss factor showed frequency dispersion at all temperatures.

Structural, morphological, optical, electrical and dielectric features based on nanoceramic Li4Ti5O12 filler reinforced PEO/PVP blend for optoelectronic and energy storage devices

Polymer nanocomposite films had been fabricated by the solution casting process using the organic matrix of polyethylene oxide/polyvinylpyrrolidone (PEO/PVP: 50/50 wt%) blend and various filling levels of lithium titanium oxide nanoparticles (Li4Ti5O12 NPs). The TEM and XRD techniques indicated the phase purity of the cubic Li4Ti5O12 NPs with a crystallite size of about 69 nm. The FTIR spectra revealed that the complexation/miscibility between the PEO/PVP blend components were existed through the formation hydrogen bonding between the main functional groups of these polymers and also the loaded NPs fundamentally behaved as geometrical incarceration for the structure of PEO/PVP matrix, due to the formation of polymer-nanoparticles interactions. The SEM images indicated observable variations in the size of PEO spherulites, formed aggregations and pores of host matrix on 1 wt% Li4Ti5O12 NPs and additional 3 and 5 wt%. The optical features of nanocomposites such as optical energy band gap and refractive index were evaluated through the UV/vis. absorbance spectra, where the redshift for the main absorption edge of the filled films implied that Li4Ti5O12 NPs had been successfully embedded into the PEO/PVP matrix. The maximum refractive index and the lowest optical bandgap energy were obtained for the nanocomposite sample (5 wt%). The AC electrical conductivity σac and the dielectric response of the prepared samples were studied, where the loaded NPs increased the values of σac, dielectric loss, and dielectric constant of the PEO/PVP blend and the dielectric constant of the nanocomposite films decreased with increasing the applied frequency. The electrical modulus formalism (M*) and impedance formalism (Z*) were used to analyze the impedance data. The enhancements in the optical and electrical characteristics make these nanocomposite materials appropriate for many uses such as integral thin film capacitors, flexible nanodielectrics for organoelectronic devices, high power Li-ion batteries, optical band gap tuner and many optoelectronic devices.

Synthesized polymeric nanocomposites with enhanced optical and electrical properties based on gold nanoparticles for optoelectronic applications

In the present work, gold nanoparticles (Au-NPs) were synthesized in two ways: plant extract and laser ablation techniques. Then, Au-NPs were added to (PVP/PVA/CMC) blend (TB) to produce novel nanocomposites using the solution casting technique. X-ray diffraction analysis, Ultraviolet and visible spectroscopy, and transmission electron microscopy provided conclusive evidence for preparing Au-NPs through the above methods. The optical, structural, and dielectric properties of the prepared samples were prudently investigated and confirmed their semicrystalline nature. TEM study concluded that Au-NPs are more uniformly distributed in the TB/AuNPs-biosynthesized (TBAu-B) matrix than in the TB/Au-NPs prepared by laser ablation (TBAu-L) matrix. The decrease in interatomic distances increases the refractive index with an enhancement in optical properties. The change in loss tangent provided a deeper discernment into the relaxation dynamics that arose inside the current films. The electric modulus formalism verified the non-Debye behavior of charge carriers inside the TB-based nanocomposite samples. It also demonstrated a remarkable capacitive feature of the nanocomposite films. The dielectric characteristics of the TBAu-B nanocomposite sample have improved, where AC electrical conductivity reached 1.58 × 10−3 S/cm. Because of this favorable enhancement, the TBAu-B nanocomposite has the potential to be utilized in optoelectronic applications such as sensors.

Influence of excitation conditions in an alternating field on kinetic and dielectric characteristics intercalated compounds Ag-=SUB=-x-=/SUB=-MoSe-=SUB=-2-=/SUB=-

Using the technique of impedance spectroscopy, data on the effect of the magnitude of the variable signal and the constant bias on the kinetic characteristics of the AgxMoSe2 samples were obtained. The effect of temperature on the parameters of the impedance spectra of the studied compounds and on their dielectric characteristics, which were analyzed within the framework of the electrical modulus formalism, is also shown. Keywords: impedance, intercalates, molybdenum diselenide, silver, permittivity, electric modulus.

Влияние условий возбуждения в переменном поле на кинетические и диэлектрические характеристики интеркалированных соединений Ag-=SUB=-x-=/SUB=-MoSe-=SUB=-2-=/SUB=-

Using the technique of impedance spectroscopy, data on the effect of the magnitude of the variable signal and the constant bias on the kinetic characteristics of the AgxMoSe2 samples were obtained . The effect of temperature on the parameters of the impedance spectra of the studied compounds and on their dielectric characteristics, which were analyzed within the framework of the electrical modulus formalism, is also shown.

Influences of crystal structure, microstructure and adsorbed CO2 on dielectric properties of Ba2YbSbO6-BaCO3 formed by mechanical activation of Ba2YbSbO6

Herein, we have reported the structural, microstructural, thermal, optical and temperature dependent dielectric properties (between 40 Hz and 5 MHz) of Ba2YbSbO6 (BYSB) synthesized by solid state ceramic method and a nanocomposite of Ba2YbSbO6-BaCO3 (BYSN). The samples are characterized by XRD, FESEM, EDS, FTIR and Raman spectroscopy. The nanosized Ba2YbSbO6 prepared by ball milling of BYSB adsorbs atmospheric CO2 leading to the formation of BYSN. The dielectric behaviours of the samples have been examined in the framework of dielectric permittivity, electric modulus and conductivity formalisms. The samples exhibit non-Debye type relaxation governed by polaron hopping. BYSN exhibits better dielectric behaviour than BYSB. It has been shown that crystal structure, grain size, grain boundary contribution and surface adsorbed CO2 strongly influence the dielectric relaxation dynamics and conduction mechanism of the samples. The dielectric response of these samples is comparable to their analogues counterparts used for fabrication of radio frequency devices.

Dielectric relaxation of α-Fe2O3/Gd2O3 core-shell nanoparticle obtained through the polyol method

The design of core-shell nanostructures is a potential approach to obtaining advanced dielectric nanocomposites. The frequency-dependent dielectric dispersion of gadolinium oxide (Gd2O3) encapsulated iron oxide (Fe2O3) core-shell nanoparticles (Fe2O3/Gd2O3 CSNPs) synthesized by the polyol route is investigated in the temperature range from 303 K to 553 K and in the frequency range from 42 Hz to 1.1 MHz. The phase formation of the materials is evaluated by X-ray diffraction analysis. Synthesized Fe2O3/Gd2O3 CSNPs have multi-core nature are found by Transmission electron microscopy (TEM). Relaxation time corresponding to dielectric loss is found to obey Arrhenius law with an activation energy of 0.26 eV. Dielectric relaxation is analyzed in the electric modulus formalism. The frequency-dependent conductivity spectra follow the Jonscher power law.

Effect of Humidity on the Electrical Response of Interdigitated Circuit Patterns

Environmental factors can play a significant role on the performance of electronic devices. This can be controlled for by designing electronic components with materials that operate suitably under the working conditions of a device. Humidity is a highly variable factor that is unavoidable in ambient conditions, capable of affecting the electrical performance of components especially when they are hydrophilic in nature. Components with such properties can allow water molecules to either permeate through or reside on the circuit surfaces over time. Due to this, it is expected that the relative humidity in the environment of hydrophilic components will vary the circuit’s performance. Previous work [1] was conducted at a single humidity of 50%RH to assess the repeatability of the measured properties. In this study, interdigitated circuits were characterized using impedance spectroscopy at multiple relative humidity levels under a fixed temperature over a frequency range of 100 mHz to 10 MHz. Five interdigitated identical circuits were fabricated on a single solder coated circuit board, followed by no additional surface treatments. The circuits on these uncoated solder boards exhibit capacitive behavior at low humidity levels as expected. With increasing relative humidity, the circuit response transitions towards resistive behavior while exhibiting a reduction in real and imaginary impedance due to increased water molecule concentration at the interfaces of the circuit. Nyquist plots exhibit this transformation as the forming of a semicircle that decreases in size with increased humidity. When the impedance data is converted to the electrical modulus formalism [2], humidity increases result in the formation of peaks in the imaginary electric modulus function as shown in Figure 1. The surface topology of the different circuits, consisting of 50 electrodes each, was examined to better understand the significant effect of relative humidity on the impedance response of the circuit. Using optical and laser microscopy, it was found that the solder coat and interdigitated combs on the uncoated boards are porous in nature and have repeated units of inhomogeneous topologies, leaving many opportunities for water to gather or permeate at surfaces between the interdigitated combs. Five distinctive regions were found to repeat across the width of the circuits. Due to this, surface roughness parameters were also examined to investigate the possible link between topology and impedance response found. Figure 1

Synergetic effects of nano-SiO2/glycerol on the electrical and optical properties of PVA for embedded electronics and optical applications

The present study aims to prepare a low-cost, eco-friendly, free-standing film with optimized physical properties. A PVA composite of hard-soft hybrid filler ratio 1:3 (nSiO2:Gl) is prepared by casting. Dynamic mechanical analyses are processed in the frequency range (0.01–9 Hz). Moreover, dielectric studies are performed in the frequency range (50 Hz–5 MHz). Herein, the modified Jonscher equation and electric modulus formalism are used to explain the results. Transmittance and reflectance of studied samples are measured in the UV–Vis range (200–700 nm). Detailed discussions of band structure, refractive index, and optoelectronic parameters are addressed. Remarkably, the results showed that mechanical and electrical properties of PVA can be tuned by careful modulation of glycerol content, whereas optical properties are more sensitive to nSiO2 content. Finally, FTIR and SEM structural analyses investigate the induced structural changes in PVA.