Electrical Properties Of Samples Research Articles

Study of multiferroic properties of Mn substituted Bi0.8Sm0.1Dy0.1Fe1-xMnxO3 ceramics

Abstract Transition metal Mn substituted various multiferroic Bi0.8Sm0.1Dy0.1Fe1-xMnxO3 (x = 0.00, 0.01, 0.03 and 0.05) ceramics samples were fabricated by the solid-state reaction technique. The distorted rhombohedral perovskite structure with some phase impurity of all samples is confirmed by X-ray diffraction analysis. Field Emission Scanning Electron Microscope and Energy Dispersive X-ray spectroscopy are used for microstructural and quantitative analysis, respectively. Densities are decreased and the average grain size is increased with Mn contents. The initial permeability and relative quality factor (RQF) have found to be increased with Mn contents in the samples. The peaks in RQF shifts toward the lower frequency region with increasing Mn contents can be attributed by Snoek’s relation. All the samples show paramagnetic behavior at room temperature and magnetization slightly increases with Mn contents. The frequency dependent dielectric constant is investigated and found to consequence of space charge polarization. The dispersion behavior in dielectric constants can be explained by the Maxwell-Wagner model. The dielectric constants and dielectric loss decrease with increasing of Mn contents for all the samples. The value of electric modulus is observed to increases with the increasing of frequency and this dispersion phenomena is due to short range mobility of charge carriers in conduction. The effect of grain and grain boundaries on electric properties of samples are investigated by complex impedance analysis. The ac conductivity increases with frequency due to small polaron hopping and it can be attributed according to Jonscher’s power law.

Structural Transformations and Formation of Microstructures and Nanostructures in Thin Films of Chalcogenide Vitreous Semiconductors

Abstract Chalcogenide vitreous semiconductors (ChVSs) are of both fundamental and applied interest as materials in which reversible structural transformations within the amorphous phase and phase transitions to the crystalline state can be effectively implemented and various microstructures and nanostructures can be obtained as a result of external effects. One of the most promising methods for such ChVS modifications is the pulsed-laser-irradiation technique, which is a noncontact technology of local impact and makes it possible to change the structural, optical, and electrical properties of samples in a wide range. This includes methods based on the precision formation of a surface microrelief and nanorelief, and high contrast in the conductivity and refractive index between the crystalline and amorphous phases. This work reviews key publications on the structural modification of thin films from the most widely studied binary and ternary ChVS compounds (As2S3, As2Se3, Ge2Sb2Te5, etc.) to show the use of irradiated samples as metasurfaces for photonic applications and promising phase-change data storage.

A study about the relationships between surface structures and electrical impedance characteristics in single-walled carbon nanotube/polyester composites

The present study aims to understand the relation between impedance characteristics and fractal behaviours. The pure and single-walled carbon nanotube (SWCNT) reinforced unsaturated polyester resin (UPR)-based composite specimens were produced by the hot press process with this aim. The Nyquist variation in the neat sample shows a straight line, which can describe the great resistance in the material and its insulating nature, while the Nyquist plots of the carbon nanotube doped sample show an almost semi-circular shape, indicating the presence of electrical conductivity. In addition, fractal analysis with statistical scaling method is used to determine the relationships between the superficial heteromorphology and electrical properties of samples. The surface particle coverage rates, fractal dimensions, cluster pattern structures, Feret diameters and Feret angles were calculated for samples. Feret angle decreases indicating that the distance between clusters is decreasing as coverage ratio, fractal dimension and Feret diameter increases.

Reductant-free synthesis conditions for water-dispersible reduced graphene oxide

Reduced graphene oxide (rGO) is the demanded material for large-scale graphene applications due to the relative ease of preparing sufficient quantities with the desired properties. Herein, optimized preparation conditions for water-dispersible rGO using the one-step chemical exfoliation method are reported. The rGO samples were obtained from graphite under different controlled reaction conditions, i.e., temperature (120, 140, and 160 °C) and time (16, 20, and 24 hrs). The microstructural, chemical, wetting, and electrical properties of samples were characterized using Raman spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, contact angle measurement, current-voltage (I–V) characteristic, and electrochemical impedance spectroscopy (EIS), respectively. The Raman parameter (i.e., the ID/IG values) was used to assess the quality of rGO materials. Accordingly, rGO160@20 showed the smallest ID/IG value (0.57) compared to the rest of the samples, followed by rGO160@16 and rGO120@24 with 0.75 and 0.77 values, respectively. The observed broad and diffused peaks centered at 2θ = 25° from XRD are the finger-print characteristics of rGO samples. FT-IR (mainly due to -OH) and lower contact angle values (≤ 33 °C) analysis confirmed the hydrophilic nature of these samples. The samples' non-linear I-V characteristics were attributed to disordered dielectric barriers. The charge transfer resistances (Rct) at the electrode/electrolyte interface were 21.65 for rGO160@20 and 25.65 for rGO160@16 and rGO120@24. EIS analysis also confirmed the rGO samples have supercapacitor behavior. Experimental parameters' synergistic effects influenced sample microstructure. Optimal processing conditions of rGO samples were also achieved for energy storage and applications that need graphene water dispersion.

Preparation and properties of K0.48Na0.52NbO3 ceramics for bone scaffolds via digital light processing

Lead-free piezoelectric ceramics are expected to be used for artificial bone scaffolds since they can generate electrical signals and promote recovery, but it is still difficult to fabricate piezoelectric scaffolds with complex structures. In this work, digital light processing (DLP) technology was used to fabricate potassium sodium niobate (K0.48Na0.52NbO3, KNN) bone scaffolds with gyroid triply periodic minimal surface. Suspension was first optimized to ensure both high solid loading (42 vol%) and high cure depth (>50 μm). KNN porous scaffolds (porosity: 60%) and other samples for tests were printed successfully. Then, influences of sintering temperature on microstructure, relative density and mechanical properties were discussed. Results showed that when sintered at 1090 °C, printed KNN ceramics had the highest relative density (90.11%) and lowest open porosity (5.75%), and exhibited the most satisfying mechanical properties (compressive strength: 33.85 MPa, elastic modulus: 1.87 GPa, flexural strength: 35.40 MPa, hardness: 2.39 GPa), which can meet the requirements of cancellous bone. Finally, the electric properties of samples at room temperature were verified. With d33 being 113.67 ± 2.49 pC/N and Pr being 19.94 μC/cm2, printed KNN ceramics showed comparable piezoelectric and ferroelectric performances with traditionally dry-pressed samples. These results indicated that DLP technology is competitive in preparing KNN piezoelectric bone scaffolds for implantation.

Influence of Ion Exchange on Photoresponsive Properties of Potassium Poly(heptazine imide)

Metal poly(heptazine imide) (MPHI) exhibits various optoelectronic functions by accommodating various metal ions in its heptazine-based graphite-like two-dimensional layer. Although potassium PHI (KPHI) is the most well-studied in MPHI series, there are unresolved issues regarding the mechanism responsible for its unique properties, particularly its high photocatalytic activity. The mechanisms underlying other diverse properties, such as photochromism and photoconduction, also remain unknown. Herein, we focused on elucidating the mechanisms of photochromism and photoconduction in KPHI. We developed a method to gradually replace K+ in KPHI with H+ and successfully prepare samples with tunable K+ concentrations. The structural, chemical, optical, electronic, and electrical properties of samples with continuously varying K+ concentrations were thoroughly investigated through various experiments and theoretical calculations. First, the gradual substitution of K+ for H+ in KPHI was investigated using X-ray photoelectron spectroscopy, X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy. XRD analysis revealed that K+ in KPHI was not randomly substituted with H+, but even small amounts of K+ substitution led to the formation of the long-range ordered region of HPHI. Absorbance measurements revealed a continuous blue shift of the absorption edge as the ratio of K+ decreased from that of KPHI. Energy band calculations revealed that the energy gap of HPHI was more than 14% larger than that of KPHI. The dependence of the K+ concentration measurements on the photochromism and photoconductive properties showed that in the K+-rich samples, the K+ released from the PHI layer upon white light irradiation had a significant effect on the electrical conduction properties. K+ conduction was dominant in the electrical conduction of KPHI, including photoconduction, under ambient conditions. However, the mobility of H+ in HPHI was very low, which was responsible for the lethargic return to the ground state after photoexcitation and minimal electrical conductivity.

Evolution of surface morphology and properties of diamond films by hydrogen plasma etching

Abstract The micron-scale diamond film was prepared using hydrogen and methane as the mixed gas supplies via self-developed 3 kW/2,450 MHz microwave plasma chemical vapor deposition (MPCVD) equipment. On this basis, the evolution of the surface morphology, hydrophobicity, and electrical properties of samples under different hydrogen plasma etching times was investigated. The results indicate that the crystal edge and the top of the diamond grain were preferentially etched when etching time is less than 30 min. The surface roughness reduced from 0.217 to 0.205 μm, and the resistance value decreases from 3.17 to 0.35 MΩ. However, as the etch time increases to 120 min, the etching depth increases, and the surface roughness was increased. Simultaneously, the contact angles increased from 62.8° to 95.9°, which indicates that the surface of the diamond films exhibits more pronounced hydrophobicity. The treatment time of hydrogen plasma has no significant effect on the resistance value in the range of 0.26–0.50 MΩ. The mechanism of surface etching by hydrogen plasma was also discussed.

Grain size effect on electrical properties of dry friable sand

AbstractThe current experiment is designed to look into the effect of pore size dispersion on the electrical properties of some friable sand samples at frequencies ranging from 10–4 to 100 kHz. A large amount of friable sand was sieved. Individual grain sizes were collected and compacted under appropriate pressure to create a sample that would later be measured electrically. The grain size dispersion covers a range from 5 mm up to 56 µm (5 mm, 3.15 mm, 2.5 mm, 1.6 mm, 1 mm, 0.75 mm, 0.5 mm, 0.63 mm, 0.4 mm, 0.25 mm, and 0.056 mm). The samples were compressed into a disk of appropriate size. The observed changes will be due solely to grain size dispersion. The electrical properties of the samples were able to recognize different grain size effects. The main dominant and controlling factor on the electrical properties of the specimens is grain size, in addition to texture or surface roughness. The electrical properties of curves revealed that the conductivity and dielectric constant increase as grain size decreases. Conductivity increases due to an increase in conducting clusters between grains, i.e., the formation of apparently semi-conducting clusters between grains. The decrease in porosity between grain sizes, i.e., the volume of air between grains, has resulted in an increase in the dielectric constant. This is accepted logically because grain size decreases the number of pore voids or throats between grains. In addition, as grain size decreases, so does the complex impedance. To the best of our knowledge, this is the first time that relationships between the electrical properties of friable sand and grain size dispersion have been studied.

Study on rapid measurement technic of dry rubber content in latex cup lump by electrical properties

Dry rubber content meter is substantial tool for Impartial trade on rubber cup lump. Department of Agriculture researchers proposed rapid measurement technic of dry rubber content in latex cup lumps by their electrical properties. Two probe types needle and roller were designed, in the first phase, constructed, installed and tested. Needle type probe of 25 mm. in length and 5 mm. apart was selected in measuring electrical properties of cup lump samples as its penetration depth is half of the thickness. Two cylindrical rollers probe of 220 mm. in length and 101.6 mm. (4 inches) in diameter powered by 2 HP gear motor were designed, constructed, installed and tested. Rubber cup lump samples were each statistical divided into 9 regularly measuring parts in needle type probe. Rubber cup lump samples in rollers type probe were typically enforced to pass through 1-inch gap between two rollers. Irregular size sample of more than 76.2 mm. (3 inches) thickness of rubber cup were sliced before measuring into 2 equal thickness pieces. Electrical properties of samples were acquired by standard electrical measuring instruments and percentage of dry rubber content were determined by standard oven method for all sample segments. As the results of this study, rubber content percentage of cup lump was correlated with electrical capacitance than resistance. Electrical capacity value of the latex cup lump from needle-type and two roller-type probes were inversely correlated with the percentage of dry rubber content within the range of 0 – 75 nF and 0 – 380 nF and coefficient of determinations were 0.90 and 0.97, respectively. These initiate features will be utilized in designing of percentage of dry rubber content prototype meter by electrical property values in the future. Percentage of dry rubber content from DRC method of lump from fresh latex and conventional cup lump by oven method was significantly correlate. Electrical properties of latex cup lump produced in the laboratory and farmers are also significantly consistent.

Deposition of copper sulfide films on polyamide surface

In this paper, we present a novel and low - cost method for preparing copper sulfide films on polyamide. Non-treated as well as pre-treated PA6 films by 3 different methods (in boiled water; in NaOH solution; in boiled water and then in NaOH solution) were used for the formation of Cu2S layers by the sorption-diffusion method. Molten sulfur has been used as a sulfurization agent. The XRD, FTIR, and UV-VIS methods were used to characterize the structural, optical, and electrical properties of samples and to track changes in samples after each treatment stage. The sheet resistance of Cu2S layers depends on the pre-treatment method and varied from 7 k?/sq to 6 M?/sq. The optical band gaps (Eg) for direct and indirect transitions are determined to be 2.61-2.67 eV and 1.40-1.44 eV, respectively. Furthermore, the optical constants n, k, and ? are determined from UV-VIS measurements.

The Study of the Copper Alloy Structure and Properties

This paper is devoted to the possibility of using tin as an alloying element in a copper alloy for the contact wire manufacture for high-speed electrified railways. To this end, laboratory experiments were carried out to determine the effect of tin on the structure, mechanical and electrical properties of samples, made of low-alloy system Cu-Sn alloys, under the cold deformation. Cast rods and rolled billets of CuSn0,2, CuSn0,4 and CuSn0,6 alloys are made. The cast rods macrostructure is studied. The analysis showed that with the introduction of tin into copper, there is no zone of columnar crystals in the macrostructure. Moreover, it was found that grains of α-solid solution of tin in copper have a shape close to equiaxial. A structure analysis of rolled billets showed that an increase in the deformation degree leads to grinding of crystalline grains. The mechanical properties of rolled billets were determined: ultimate tensile strength σU, offset yield strength σ0.2 and elongation δ50. The dependence of the electrical resistivity of rolled billets on the deformation degree and the tin content in the alloy is determined. Еhe higher the tin content in the alloy and the deformation degree is, the higher is the electrical resistivity. The electrical resistivity of samples, made of CuSn0.2 and CuSn0.4 alloys, coincides with the GOST R 55647-2018 requirements. The laboratory studies have shown that tin-containing copper alloys (Sn is up to 0.4 wt. %) can be recommended as a material for the manufacture of contact wire.

Nanostructured quaternary Ni1-xCuxFe2-yCeyO4 complex system: Cerium content and copper substitution dependence of cation distribution and magnetic-electric properties in spinel ferrites

Quaternary Ni1-xCuxFe2-yCeyO4 complex nano-ferrites system with different cerium content ratio and copper substitution degree were synthesized via co-precipitation wet chemical technique. The newly obtained nanoparticles, with general formula Ni1-xCuxFe2-yCeyO4 (where x = 0.0, 0.3, 0.6 and y = 0.00, 0.03, 0.05, 0.08 and 0.10) were heated up to 600 °C to stabilize the specific crystalline spinel structure. The limit of cerium content was quantitively determined to be around 0.08 and up to 0.10. Furthermore, the powders were pelletized in a 13 mm wide pellets and thermally treated at 950 °C. The thermal treatment affected even more the phases segregation process, as CeO2 was identified in the sample with lowest degree of cerium insertion – 0.03. Also, a difference in color and size of pelletized samples was noticed after the 950 °C thermal treatment. The Rietveld refinement, crystal structure confirmation, morphology magnetic and electrical properties of samples have been deeply studied. The cation distribution carried out from Rietveld refinement confirms the occupancy of (Fe3+) on tetrahedral sites and [Ni2+], [Cu2+], [Fe3+] and [Ce2+] on octahedral sites in the crystal lattice. Preliminary information regarding the cation distribution in spinel structures were suggested by FTIR spectral results, precisely in the 650-520 cm−1 region, as a consequence of peak shape and lack of shiftiness of MTd – O bond. Spherical-shaped quaternary nano-ferrites of 17–28 nm were determined from FE-SEM analysis and the samples composition was confirmed by EDX analysis. Hysteresis loops shows modifications in coercivity, magnetization and magnetic remanence with Ni2+ and Cu2+ ions doping in Ni1-xCuxFe2-yCeyO4 complex systems with typical ferrimagnetic behavior. Dielectric measurements were employed in order to determine the electrical permittivity, dielectric losses and conductivity values in a 10 Hz – 1 MHz frequency range.

Influence of the polymer molecular weights on the electrical properties of Poly(vinyl alcohol) – Poly(ethylene glycols)/Graphene oxide nanocomposites

Graphene has unique electrical properties at room temperature properties with a flexible 2D layer and stronger material over discovered and use to enhance the electrical properties of materials. This study investigated the influence of two important factors the molecular weights (Mw) of polymer and the concentration of nanofillers on the electrical properties of samples. Hybrid nanocomposites were fabricated from polyvinyl alcohol (PVA) and polyethylene glycol (PEG) with three different molecular weights (4 k, 8 k, and 20 k) using developed mixing-sonication-solution methods. This method was successfully exhibited a fine homogeneity and good dispersion of both polymers and nanofillers in the matrix as displayed by using an optical microscope (OM). The effect of the addition of graphene oxide on the alternating electrical properties showed a reduction in the dielectric constant and the isolation loss of the polymer compounds (PVA-PEG-GO) with increasing the frequency of the electric field and the loss of isolation increased. It was also shown that the increase of electrical conductivity is noticeable with samples by increasing the molecular weight of PEGs to the highest at 20 k Mw. Increasing the polymer molecular weight in addition to the contribution of GO revealed an extraordinary improvement of the electrical properties that bring promising and performance materials for electronic, photovoltaic devices, heterojunction, solar cells, and energy storage systems, other substantial applications.

Investigations on the Structural and Electrical Properties of Sm3+-Doped Nickel Ferrite–Based Ceramics

Compositions of ferrimagnetic NiSmxFe2−xO4 (0.00 ≤ x ≤ 0.25) ceramics were synthesized by the self-propagating sol-gel autocombustion method. Structural information was found using X-ray diffraction. It reveals that all the ceramics possess cubic symmetry of spinel ferrite with a small amount of orthoferrite phase SmFeO3, which is a ferroelectric material. The amount of phases and lattice parameter were determined by the Rietveld refinement method using the Fullprof suite software. As doping concentration increases, the secondary phase fraction of the ferroelectric SmFeO3 also increases. Due to the increase of the ferroelectric phase in NiFe2O4, the electrical properties of doped samples also modify. To know this modification, the electrical properties of these samples have been investigated. The room temperature dielectric and complex impedance analysis have been measured in the frequency range of 1–106 Hz. The dielectric behavior for x = 0.05 concentration (NiSm0.05Fe1.95O4) has a maximum dielectric constant value with a minimal loss tangent. Cole-Cole plot brings out the role of grain and grain boundaries in the bulk. Using impedance study, the resistance and capacitance of grain and grain boundaries have been determined. The ferroelectric behavior has been performed through the P-E (polarization versus electric field) and J-E (leakage current versus electric field) curves at room temperature.

Effects of particle size on the electrical properties of NdFeO3 nanoparticles

In this paper, NdFeO3 nanoparticles were synthesized by the co-precipitation method. The particle size of NdFeO3 nanoparticles was controlled by changing the NaOH concentration in the co-precipitation method, mainly because NaOH concentration could control grain growth. The samples were characterized by X-ray diffraction (XRD) and filed-emission scanning electron microscopy (FE-SEM). They were found that with the change of NaOH concentration, the lattice parameters and cell volume of NdFeO3 nanoparticles changed little, but the average particle size ranged from ~ 100 to ~ 142 nm. And the influence of particle size on electrical properties of samples was also explored. The results showed that the dielectric constant of the sample increased with the decrease of the average particle size, and the dielectric loss decreases. When the average particle size was ~ 100 nm and the frequency was 103 Hz, the dielectric constant (e′) was at most (~ 1.4 × 104) at room temperature, indicating that it had potential applications in dielectric capacitors. In addition, the conduction mechanism of NdFeO3 nanoparticle was studied by frequency dependence of AC conductivity. The effect of the grain and grain boundaries of NdFeO3 nanoparticles on the electrical properties of material was observed in complex impedance spectroscopy. The grain boundary resistance played a leading role in the resistance of the material, and the values of resistance increased with the decrease of the particle size.

Thermal expansion and electrical properties of Fe-doped CaCu3Ti4O12 ceramics

Thermal behavior and electrical properties of Fe-doped CaCu3Ti4O12 ceramics samples have been studied by high-temperature X-ray diffraction, thermal analysis, and impedance spectroscopy. According to X-ray diffraction data, samples of CaCu3Ti4-4хFe4хO12-δ and CaCu3-3хFe3хTi4O12+δ composition do not contain iron-containing impurity phases; in trace amounts may contain copper oxide (II). According to thermogravimetry data, no weight loss of samples was recorded before the melting start temperature (~1033 °C). The DSC curves of doped calcium-copper titanate samples show an exothermic effect in the range of 506–573 K, not associated with a phase transition, and an endothermic process, at a temperature above 1219 K, due to the dissociation of CuO. The thermal expansion coefficient for CaCu3Ti3,76Fe0.24O12-δ in the range of 298–1193 K changes continuously from 8.6 × 106 (298 К) to 11.4 × 106 °С−1 (1173 К). Based on the results of impedance spectroscopy, the electrical properties of the samples were simulated and an equivalent scheme was proposed. The samples exhibit ionic conductivity. The activation energy of conduction of the CaCu3Ti3.76Fe0.24O12-δ is 0.65 eV and 1.04 eV of the CaCu3-3хFe3хTi4O12+δ.

Phase Equilibria Thermodynamic Analysis, and Electrical Properties of Samples in the System Li2O–B2O3–Yb2O3

Samples in the Li2O–B2O3–Yb2O3 system were synthesized and studied by differential thermal analysis, X-ray powder diffraction analysis, and thermodynamic analysis. Polythermal sections and an isothermal section of the phase diagram of this system were constructed. It was shown that the polythermal sections Li2O ⋅ 3B2O3–Yb2O3 ⋅ B2O3 and Li2O ⋅ B2O3–Yb2O3 ⋅ B2O3 are non-quasi-binary, and Li2O ⋅ 2B2O3–Yb2O3 ⋅ B2O3 and Li6Yb(BO3)3–YbBO3 are quasi-binary. The isothermal section in the Li2O–B2O3–Yb2O3 system at 25°C has 15 stable tie lines, which divide the system into 14 triangles of coexisting phases. The compounds 6Li2O ⋅ Yb2O3 ⋅ 3B2O3 and 3Li2O ⋅ 2Yb2O3 ⋅ 3B2O3 were synthesized, and their physicochemical properties were studied. The temperature dependences of the electrical conductivity of polycrystalline samples in the Li2O–B2O3–Yb2O3 system at direct current were investigated. The activation energies of the conduction of semiconducting samples were determined. It was observed that, with adding Yb2O3 (x = 0–0.02), the electrical conductivity of samples of the composition (1 – x)Li2O ⋅ 3B2O3–xYb2O3 ⋅ B2O3 decreases, and the activation energy increases from 0.87 to 0.94 eV.

A strategy for improving sinterability and electrical properties of gadolinium-doped ceria electrolyte using calcium oxide additive

In this study, Gd and Ca co-doped ceria electrolytes with the compositions of Ce0.8Gd0.2–xCaxO2–δ (x = 0–0.08) were prepared by a novel gel-casting method. The effects of the addition of Ca on the phase compositions, sintering behavior, and electrical properties of samples were investigated. According to the scanning electron microscope results and relative density measurement results, it is found that the addition of particular quantity of CaO can promote the sintering densification with a uniform grain growth. When the sintering temperature is 1400 °C, the sample with 6 mol% addition of Ca has the highest relative density, which reaches 98.5% of the theoretical density. The electrical properties testing results confirm that the electrical conductivity of the samples can be improved significantly by doping appropriate CaO content. The maximum conductivity of 0.082 S/cm can be obtained at 800 °C in the Ce0.8Gd0.12-Ca0.06O1.87 sample. It suggests that CaO can be used as an effective sintering aid and a co-dopant on the optimization of electrical properties for ceria-based electrolytes.

Influence of the Formation Conditions and Parameters of Defects on Carrier Transport in Nanocrystalline Cobalt Oxide

The structural and electrical properties of samples made of nanostructured cobalt oxide prepared by thermal decomposition and electrospinning (as well as the characteristics of their paramagnetic defects) have been investigated. A correlation is found between the conductivity of the obtained material and its structural parameters, depending on the synthesis method. It is revealed by electron spin resonance (ESR) spectroscopy that the conductivity of nanostructured cobalt oxide is determined by both the concentration of defects and their characteristics.

The Effect of Various Annealing Cooling Rates on Electrical and Morphological Properties of TiO2 Thin Films

This paper presents the effect of different cooling rate after annealing on structural and electrical properties of TiO2 thin films. Titanium dioxide thin film was deposited on a silicon substrate using DC magnetron technique. After annealing TiO2 thin films at 600oC, to investigate the effect of different cooling rates on TiO2 thin films, samples were cooled down from 600oC to the room temperature under 3 different rates: 2oC/min, 6oC/min and 8oC/min. The Surface morphology, crystal structure, and electrical property of samples were characterized by atomic force measurement (AFM), X-ray diffraction (XRD) and Four-point probe (FPP) technique. It is found that the rate of decreasing temperature after annealing can affect the morphology structure and electrical resistivity of titanium dioxide. Sample with 2oC/m has the biggest grain size, and more electrical resistivity while the smallest grain size and lowest electrical resistivity belong to sample with 8oC/m cooling rate.