Unannealed Samples Research Articles

Cold Atmospheric Plasma Annealing of Plasmonic Silver Nanoparticles

Silver nanoparticles deposited on quartz substrate are annealed by cold atmospheric plasma jet to tailor the surface plasmon resonance (SPR) of silver nanoparticles. SPR is the unique optical property which arises due to the interaction of electromagnetic waves with the conduction electrons on the metal nanoparticle surface. The collective oscillations of these conduction electrons at specific EM wavelengths leads to strong scattering and absorption. For silver nanoparticles (AgNPs), the SPR occurs in UV-visible region and therefore AgNPs are used in various applications including solar energy harvesting, light emitting diodes, printed optoelectronic devices, and surface enhanced Raman scattering(SERS). The SPR absorbance peak strongly depends on the size, shape and assembly of the metal nanoparticles. The SPR absorbance peak can be tailored by thermal annealing of AgNPs. The annealing or sintering leads to change in mean diameter of nanoparticle due to agglomeration or reduction in the outside oxide layer of nanoparticles and therefore either red or blue shift in SPR is observed. However, thermal annealing is not always desirable, especially for the flexible polymer substrates. In the present work, we demonstrate the efficacy of cold atmospheric plasma annealing to achieve desired thermal annealing effects at room temperature. Silver nanoparticle films were deposited on the quartz substrate by injecting NP aerosol in the flowing argon gas. As deposited AgNP films were annealed by low temperature atmospheric plasma jet for 5 mins, 10 mins and 15 mins. Fig 1(a) shows the optical absorption spectra for un-annealed as well as annealed AgNP films. For un-annealed sample we observed the SPR absorbance peak at 426 nm. This peak was blue shifted by 14 nm, 36 nm and 62 nm for plasma annealed films for 5 min, 10 min and 15 min respectively. The AgNP films were also annealed using rapid thermal processing (RTP) at 100°C, 250°C, and 400°C for 5 min, 10 min and 15min. For all the temperatures, SPR peaks were blue shifted and for 400°C (corresponding the thermal energy of 58 meV) the blue shift values coincided with the values observed for plasma annealed AgNP films at room temperature. The plasma treated AgNP films were used as SERS substrates for Raman scattering studies of cortisol biomolecule. The Raman scattering signal from plasma annealed AgNP film was two times higher than that of bare quartz substrate. Figure 1

Thermoluminescence of annealed synthetic quartz: The influence of annealing on kinetic parameters and thermal quenching

The thermoluminescence of synthetic quartz annealed at various temperatures up to 900 °C is reported. Glow curves measured at 1 oCs−1 following beta irradiation to 40 Gy from a sample annealed at 500 °C and from an unannealed one consist of a prominent peak at 70 °C and secondary peaks at 110, 180 and 310 °C. In comparison, the glow peak from the sample annealed at 900 °C consists of three peaks but with the main peak at 86 °C and other lower intensity peaks at 170 and 310 °C. Kinetic analysis was carried out on the main peak only in each case. The order of kinetics of this peak was determined to be first order using various methods. The activation energy was evaluated as an average of 0.90±0.02eV for the unannealed sample and the one annealed at 500 °C. However, when the synthetic quartz is annealed at 900 °C, the activation energy decreases to 0.65±0.02eV. The main point of interest however concerns thermal quenching. It was noted that for the sample annealed at 500 °C as well as the unannealed one, the maximum intensity of the main peak decreases with heating rate. This phenomenon is associated with thermal quenching. When the same experiment is carried out using quartz annealed at 900 °C and irradiated to the same dose, namely 40 Gy, the intensity increases with heating rate. This would imply that this sample is not affected by thermal quenching. Using the notion that the radiative and non-radiative recombination routes are competitive, we repeated the experiment using a low dose of 3 Gy. In this case, the intensity decreased with heating rate showing that the process can be tuned. The activation energy for thermal quenching for the samples annealed at 900 °C, 500 °C and unnannealed one was found as 0.65±0.02eV, 0.82±0.02eV and 0.95±0.06eV. Evidently, annealing affects recombination processes in synthetic quartz.

Influence of annealing on thermoluminescence of natural quartz: Kinetic analysis and experimental study of apparent inverse thermal quenching

The influence of annealing on the main thermoluminescence glow-peak of natural quartz is reported. For comparison, results from un-annealed quartz are included. The glow-curve measured at 1 °Cs−1 after beta irradiation to 50 Gy revealed six peaks each for quartz annealed at 800 °C for 1 h and the un-annealed sample. The main peak in both quartzes was observed at 72 °C. This report focusses on kinetic analysis of the main peak. The analysis was carried out using various methods consisting of the initial rise, whole glow-peak, peak shape, variable heating rate and phosphorescence-based methods. The activation energy obtained using the various methods ranges between 0.91±0.01eV and 1.19±0.03eV for the annealed sample and between 0.93±0.01eV and 1.26±0.12eV for the un-annealed sample. The result suggests that annealing has little effect on the activation energy. The luminescence intensity decreased with heating rate in the un-annealed sample in a manner suggestive of thermal quenching. In contrast, the dependence of intensity on heating rate in the annealed sample is influenced by the dose the sample is irradiated to. Whereas thermal quenching was noted for a dose of 50 Gy in the un-annealed sample, the annealed sample showed evidence of thermal quenching at a low dose of 3 Gy with the opposite effect when irradiated to 50 Gy. The activation energies of thermal quenching were found as 0.89±0.06eV and 0.99±0.02eV for the un-annealed and annealed samples respectively. We ascribe the apparent dependence of thermal quenching on dose in the annealed sample to competition between radiative and non-radiative transitions at the recombination centre.

Remarkably Enhanced Room-Temperature Hydrogen Sensing of SnO₂ Nanoflowers via Vacuum Annealing Treatment.

In this work, SnO2 nanoflowers synthesized by a hydrothermal method were employed as hydrogen sensing materials. The as-synthesized SnO2 nanoflowers consisted of cuboid-like SnO2 nanorods with tetragonal structures. A great increase in the relative content of surface-adsorbed oxygen was observed after the vacuum annealing treatment, and this increase could have been due to the increase in surface oxygen vacancies serving as preferential adsorption sites for oxygen species. Annealing treatment resulted in an 8% increase in the specific surface area of the samples. Moreover, the conductivity of the sensors decreased after the annealing treatment, which should be attributed to the increase in electron scattering around the defects and the compensated donor behavior of the oxygen vacancies due to the surface oxygen adsorption. The hydrogen sensors of the annealed samples, compared to those of the unannealed samples, exhibited a much higher sensitivity and faster response rate. The sensor response factor and response rate increased from 27.1% to 80.2% and 0.34%/s to 1.15%/s, respectively. This remarkable enhancement in sensing performance induced by the annealing treatment could be attributed to the larger specific surface areas and higher amount of surface-adsorbed oxygen, which provides a greater reaction space for hydrogen. Moreover, the sensors with annealed SnO2 nanoflowers also exhibited high selectivity towards hydrogen against CH4, CO, and ethanol.

Thermal annealing and single–domain preparation in tetragonal Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 crystal for electro–optic and non–linear optical applications

The relaxor–PbTiO3 single crystal has attracted extensive attention in ultrasound transducers, sensors, actuators, and optoelectronics devices due to its excellent piezoelectric response and electro–optic properties. Preparation of a single–domain crystal as a critical process for application in electro–optic and non–linear optical devices suffers from serious and inevitable cracking. Therefore, a pre-poling thermal annealing process was suggested to release residual stress from crystal growth and the ferroelectric–paraelectric phase transition, which significantly reduced the chance of cracking. The effect of thermal annealing on dielectric properties, strain behavior, and domain structure were investigated. As a result, a significant increase of the dielectric constant near room temperature was obtained after annealing, which is close to the dielectric constant of the a-oriented domain. The annealed single crystal showed a lower and sharper strain peak at the coercive electric field compared with the unannealed sample, and the 90° domain walls completely vanished, which was verified by optical microscopy. The crack–free single–domain crystal showed excellent optical quality, with high transmittance of approximately 70% in the visible and near–infrared regions, which indicates that this crystal is a promising candidate for applications in electro–optic and non–linear optical devices.

Amorphous to crystalline phase transformation and band gap refinement in ZnSe thin films

Zinc selenide (ZnSe) thin films are deposited by physical vapor deposition on indium tin oxide (ITO) substrates with different thicknesses. The crystalline phase refinement is studied by carrying out post-deposition annealing in air at various temperatures. The composition analyses carried out by the Rutherford backscattering spectroscopy have shown the ratios of Zn:Se to be 1:1. As-deposited samples have shown predominant crystalline phase with a small inclusion of the amorphous phase. The contribution of amorphous phase diminishes after the post-deposition annealing of the samples in air. However, the peaks of tin oxide and ITO begin to appear in the X-ray diffraction patterns after post-deposition annealing, showing that substrate material has started reacting with ZnSe films. The crystallinity of the ZnSe samples increases with annealing temperature, which results in the increase of conductivity and optical bandgap of the samples. It is proposed that as-prepared un-annealed samples grow with a large population of trapping centers filled with electrons near the top edge of the valance band. These electrons are elevated to the conduction band when exposed to the light, resulting in a very high photo current in as-prepared samples in comparison with post-annealed samples. The population of the localized trapping centers near the top edge of the valence band of ZnSe diminishes significantly with the post-annealing that refines the band gap; optimize their electrical and optical properties.

Bridgman growth and luminescence properties of CdMoO4 single crystal

CdMoO4 single crystal was grown successfully by vertical Bridgman method. The as-grown CdMoO4 crystal presents blue-green color due to the existence of oxygen vacancies, while the color will become light even disappeared by annealing in air atmosphere as a result of oxygen introduction. The transmissivity of unannealed and annealed CdMoO4 crystals reached 60% and 78%, respectively. The photoluminescence peak of annealed CdMoO4 is located at 535 nm, and the emission intensity is obviously higher than that of unannealed sample, indicating that the annealing is favorable to improve the photoluminescence intensity. The X-ray excited luminescence of unannealed CdMoO4 crystal is very weak with low signal-noise ratio due to the strong self-absorption phenomena in crystal. For annealed crystal, the X-ray excited luminescence peak is located around 525 nm. The peak deviates about 10 nm wavelength from the peak of photoluminescence spectra due to the much deeper X-ray penetration.

Cryptomelane-type manganese oxide (KMn8O16) nanorods cathode materials synthesized by a rheological phase for lithium ion batteries

Cryotolerance-type manganese oxide (KMn8O16) nanorods were prepared for the first time by a rheological phase reaction method. The KMn8O16 samples were characterized by X-ray diffraction, scanning electron microscopy, the effects of different annealed temperatures on the morphologies and electrochemical properties of the final products were systematically investigated. The result that the annealed samples exhibit the superior electrochemical performances compared to the unannealed sample. The KMn8O16 nanorods annealed at 400 °C show the highest reversible discharge capacity (147.9 mAh/g even after 80 cycles) at current density of 50 mA/g and the best cycling stability. These results indicate that the KMn8O16 nanorods could be a promising cathode material for lithium ion batteries.

The effect of annealing and beta irradiation on thermoluminescence spectra of α-Al2O3:C,Mg

The effect of annealing on thermoluminescence spectra of beta irradiated α-Al2O3:C,Mg has been studied. Measurements were made on an un-annealed sample and samples annealed at 600, 700 and 900°C. A glow curve measured at 1°C/s from samples irradiated to 1Gy shows a high intensity peak at 163°C and six secondary peaks of weaker intensity at 43, 73, 195, 280, 329 and 370°C. When the samples are annealed at 700 or 900°C, an additional secondary peak appears at 100°C. The thermoluminescence spectrum of an un-annealed sample measured at 1°C/s between 300 and 700nm shows the main emission band at ~ 410nm and subsidiary emission bands at ~ 325 and 485nm. The emission from samples annealed at 700 and 900°C show similar bands except for a decrease in intensity of the emission at 485nm. The emission bands at 325, 410 and 485nm are attributed to F+, F and F22+(2Mg) -centres respectively. The decrease of the emission band at 485nm is deduced to be due to the destruction of the F22+(2Mg) centre at 700°C. The emission bands are unaffected by irradiation dose between 10 and 320Gy. However, when the sample is annealed at or beyond 700°C, any effects on the F+ and F centres emission can be easier distinguished particularly for doses greater than 10Gy.

Controlling metal-insulator transition in (010)-VO2/(0001)-Al2O3 epitaxial thin film through surface morphological engineering

Surface morphological control of the metal-insulator transition behaviors of VO2 epitaxial thin films is achieved by annealing substrates of (0001)-Al2O3 single crystals. The well-defined terraces of the (0001)-Al2O3 substrates are formed by annealing in air at 1200°C. Correspondingly, the surface roughness dramatically decreases in the VO2 epitaxial thin films on the annealed substrates, compared with that on the unannealed substrates. The order of magnitude of the resistivity change ratio (~ 102) of annealed samples across the metal-insulator transition (MIT) decreases by a factor of one, compared with that (~ 103) in unannealed samples. This result is ascribed to grain size effect in the VO2 epitaxial thin films. Moreover, the MIT temperature is reduced in the annealed samples with various thickness, compared with the unannealed ones. A reduction of 14.4K of the MIT temperature is observed in the thinnest VO2 films on the annealed substrates, compared with the unannealed samples. This behavior results from a compressive strain along the V-V atom chains in the annealed samples, which modifies the orbital occupancy of the V4+ ions. While increasing the film thickness, the MIT change ratio keeps on the order of magnitude 102, and the MIT temperatures of the VO2 films on the annealed substrates becomes closer and closer to those of the unannealed samples due to the weakened substrate effect. This work suggests a promising approach to decrease the MIT temperature and still maintain a moderate change ratio for the MIT, potentially enabling room-temperature electronic devices based on VO2 thin films.

Investigation Of the low-dose-thermoluminescence characteristics of LiF:Mg,P

Thermoluminescence (TL) characteristics of LiF:Mg,P with varying concentrations (0.4%, 1% and 2%) of phosphorous are investigated and compared with those of the widely used TLD-100. The TL glow curves of the three LiF:Mg,P samples exhibited two apparent peaks around 120°C and 239°C. The TL response of each of the two peaks vary linearly with increasing dose (between 0.4mGy and 12.0mGy) for each of the three samples. The thermolumiscence intensities from samples with 0.4%, 1.0% and 2.0% of phosphorous concentration were respectively at least 26, 18 and 21 times that of TLD-100. TL response from a repeat use of a single aliquot of the samples with 0.4%, 1.0% and 2.0% of phosphorous concentration did not vary by more than 6%, 8% and 10% respectively. There were 3%, 10% and 12% fading of TL response over three-week storage period at room temperature for samples with 0.4%, 1.0% and 2.0% of phosphorous concentration. Pre-irradiation annealing up to 600°C did not affect the glow curves structures of all the samples. However, while the sensitivity of samples B and C did not change with the annealing, the intensity of sample A first decreased with temperature up to 500°C before it significantly rose to a value above that of the unannealed sample. TL intensity of the sample annealed at 500°C decreased with increasing annealing duration up till one hour beyond which it remains constant. The linearity of the dose-response, negligible fading of response and unchanged sensitivities with pre-irradiation annealing for samples B and C qualify them as suitable TL dosemeters.

Self-organized, size-selection of precipitates during severe plastic deformation of dilute Cu-Nb alloys at low temperatures

High pressure torsion (HPT) experiments have been carried out at very low temperatures (−78 °C) on dilute Cu-Nb alloys. The samples were prepared by magnetron sputtering to create solid solutions containing nominally between 1 at.% and 10 at.% Nb. Some samples were pre-annealed to 700 °C to form large Nb precipitates, ∼75 nm in radius, prior to HPT. For the unannealed alloys, HPT at low temperatures led to alloy decomposition for alloys with concentrations greater than ∼2 at.% Nb, with the steady state concentration of Nb increasing from ∼1.5 to ∼3 at.% as the initial concentration of Nb was increased. It was also observed that BCC Nb precipitates formed during low-temperature HPT, with a steady state precipitate size ∼10 nm in radius, which was insensitive to alloy concentration. HPT of pre-annealed Cu-10 at.% alloy led to the same steady state microstructure as the unannealed sample, indicating that the steady state during the low temperature HPT process is independent of the initial state for these Cu-Nb alloys. A model for phase evolution in strongly immiscible alloys during severe, low-temperature deformation is offered and implemented through kinetic Monte Carlo simulations. Good agreement with experiment is obtained.

Temperature dependence of optically stimulated luminescence of α-Al 2 O 3 :C,Mg

Abstract Thermal assistance and thermal quenching are two independently acting thermodynamic phenomena that simultaneously affect the stimulation of luminescence. We have studied thermal assistance to luminescence optically stimulated from α-Al2O3:C,Mg. Since thermal assistance causes only a minor change in the luminescence intensity, measurements were made after the sample had been pre-exposed to stimulating light to reduce its intensity significantly, that is, in the slow component of its decay curve. The luminescence intensity was monitored as a function of measurement temperature between 30 and 130 °C. The intensity goes through a peak at 60 °C due to competing effects of thermal assistance and thermal quenching. The initial increase of intensity is attributed to dominant thermal assistance whereas the subsequent decrease of intensity is ascribed to dominant thermal quenching. The activation energy for thermal assistance was calculated for the main electron trap of an un-annealed sample as 0.324 ± 0.020 eV and in a sample annealed at 900 °C as 0.416 ± 0.028 eV. Implications of such differences in the value of the activation energy for thermal assistance are considered.

Investigation of the effect of anodization time and annealing temperature on the physical properties of ZrO2 thin film on a Si substrate

This research work studied the effects of various anodization times (5, 10, 15, 20 and 25 min) and various annealing temperatures (500, 600, 700, 800 and 900 °C) on ZrO2 thin film on a Si substrate. The ZrO2 thin film was prepared via sputtering and anodization processes on a Si substrate. The existence of Si, SiO2, m-ZrO2, t-ZrO2 and ZrSiO4 was confirmed by x-ray diffraction, Fourier transform infrared microscopy and Raman spectroscopy. In addition, NaOH was observed as a residue on the surface of the thin film. The grain size and microstrain of both m-ZrO2, and t-ZrO2 were calculated using the Williamson–Hall and/or Scherrer equation. The morphology of samples was examined by scanning electron microscopy. In contrast to unannealed samples, the annealed samples have a smaller grain size, less NaOH, and SiO2 with a smoother surface. However, the SiO2 existed when being annealed at higher temperatures (⩾800 °C).

Facile Fabrication of Manganese Oxide/Carbon Nanotube and Its Application for Lead Removal

MnO2/C composite nanotubes (MnO2/C-CNTs) have been prepared with carbon nanofibers from the electrospinning PAN fiber, which are soaked in potassium permanganate then annealed in a furnace. The morphology of the MnO2/C-CNTs and the manganese loading amount is tunable by adjusting the soaking time and the potassium permanganate solution concentration. The manganese state is studied by XRD and XPS. The MnO2/C-CNTs had an adsorption ability to lead ions. The maximum adsorption capacity approach is found to be 283mg/g，double higher than that of unannealed samples. The data at adsorption equilibrium are suited to the Langmuir model.

Noncovalent Molecular Heterojunction: Structure Determination and Property Characterization using Scanning Tunneling Microscopy/Spectroscopy and Theoretical Calculations

Noncovalent molecular heterojunctions (MHJs) formed by the stacking of p-type (electron donor) and n-type (electron acceptor) compounds are essentially important for various optoelectronics as well as molecular devices. Herein we report the construction of the fluorinated copper(II) phthalocyanine (F16CuPc; n-type, acceptor)–polymer NTZ12 (p-type, donor) MHJ via annealing of the film of F16CuPc and NTZ12. Scanning tunneling microscopy and density functional theory calculations validate the formation of the F16CuPc–NTZ12 MHJ at the single molecular level. The constructed MHJ shows a distinctive rectifying effect in the statistical data of scanning tunneling spectroscopy because of the different barriers in two directions of electron tunneling. In the proof-of-concept photocurrent tests, the F16CuPc–NTZ12 MHJ produces much higher current under radiation than in the dark due to its well-organized donor–acceptor interface formed by annealing, whereas the current of the unannealed samples shows almost no respo...

Cooling and Annealing Effect on Indentation Response of Lead-Free Solder

With the development of lead-free solders in the electronic packing industry, Sn–Ag–Cu solders are one of the most promising lead-free alloys to be applied due to their outstanding mechanical property and wettability. By performing indentation experiments, the effect of cooling rate on the mechanical properties of Sn–3.0Ag–0.5Cu (SAC305) solder is investigated in typical cooling conditions (i.e., furnace cooled and water quenched) and compared with the as-machined samples of bulk solder bars from the industry. Based on continuous stiffness measurement technique, Young’s modulus and hardness are reduced by 2.3–3.9[Formula: see text]GPa and 0.053–0.085[Formula: see text]GPa, respectively, after annealing treatment for the indentation depth between 1000[Formula: see text]nm and 1100[Formula: see text]nm in samples after cooling, however, the value of hardness is independent of cooling condition. By defining the contact stiffness to represent residual stress in solder samples after cooling and annealing process, an exponential-based Oliver–Pharr model is employed to fit the unloading responses of indentation. It is found that the smaller cooling rate induces less contact stiffness and thus less residual stress. Despite different cooling conditions, the contact stiffness of unannealed and annealed solder samples are 711.8–842.5[Formula: see text][Formula: see text]N/nm and 655.2–673.4[Formula: see text][Formula: see text]N/nm, respectively. Thus, annealing treatment of 210[Formula: see text]C for 6[Formula: see text]h can effectively alleviate residual stress to a similar level for SAC305 solder samples with different cooling conditions. This conclusion is supported by the alleviation of pile-up deformation in the residual indentation after annealing treatment.

Effect of lead on the thermal dispersion of continuous polycrystalline copper films

It has been found that the kinetics of heating has an essential effect on copper films dispersion temperature. Annealing of nonequilibrium defects slightly slow down the diffusion processes in comparison with unannealed samples and it naturally increases the temperature of de-wetting of continuous films. It has been shown that the formation of liquid lead in continuous Cu-Pb polycrystalline films accelerates their thermal dispersion compared to the copper films of the same thickness. Minimum concentration of lead that can stimulate de-wetting of polycrystalline copper films of 50 nm thickness, is 3 wt %. Structural studies using electron and X-ray diffraction have shown that Cu and Cu-Pb films annealing and dispersing do not result in new phases and crystalline modifications. Only a slight increase in the solubility of the given system in comparison with bulk samples was found. The activation energy of de-wetting processes in Cu and Cu-Pb films, (which is equal to 1.6 and 0.2 eV respectively) has been determined by means of electron microscopic studies of kinetics of through pores growth. This process may be considered as the liquid phase mass transfer not the diffusive one due to the low activation energy of de-wetting for the films containing lead.

Effect of annealing time on properties of spinel LiNi0.5Mn1.5O4 high-voltage lithium-ion battery electrode materials prepared by co-precipitation method

In this wok, a series of LiNi0.5Mn1.5O4 (LNMO) samples with an octahedral shape entirely composed of (111) crystal planes were prepared by calcining the mixture of the precursor Ni0.25Mn0.75(OH)2 and LiOH·H2O at 800 °C for 15 h in air, followed by annealing them at 600 °C for different dwelling times. Powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and several electrochemical technologies were used to investigate the effect of annealing time on properties of the LNMO samples. XRD analysis indicates that the lattice parameters of the LNMO samples show a decreasing trend with increasing of annealing time, and the impurity peaks become less apparent for the sample annealed for 6 h and almost disappear for the samples annealed for 9 and 24 h. SEM results show that the annealing time has no obvious influence on the morphologies of the LNMO samples. Electrochemical measurements show that the electrochemical performances (capacity, cycle life, and rate capability) of the samples annealed for 6, 9, and 24 h are better than those of the unannealed sample, and the sample annealed for 9 h shows the best electrochemical properties among them due to its superior electrochemical kinetics of Li+ insertion/desertion.

Electrical and Structural Properties of PVDF/Mgo (7%) Nanocomposites Thin Films at Various Annealing Temperatures

Abstract—Poly (vinylideneflouride)/nano-magnesium oxide (PVDF/MgO) film with 7% MgO loading percentage was annealed at various annealing temperatures ranging from 70°C to 150°C. The PVDF/MgO thin film was fabricated using spin coating technique with a metal-insulator-metal (MIM) configuration. The dielectric and electric properties of PVDF/MgO with respect to annealing temperatures was studied. The PVDF/MgO nanocomposites thin films annealed at temperature of 70°C (AN70-PVDF/MgO) showed an improvement in the properties; dielectric constant value of 26 at 1 kHz frequency compared to un-annealed sample (UN-PVDF/MgO), which is 21 at the same frequency. As the annealing temperatures were increased from 90°C (AN90) to 150°C (AN150-PVDF/MgO), the dielectric constant values were found to gradually decreased from 25 to 12 respectively, which was lower than the UN-PVDF/MgO thin films. AN70-PVDF/MgO also produced relatively low tangent loss (tan δ). The resistivity value of AN70-PVDF/MgO was also found to increase from 3.08x104 Ω.cm (UN- PVDF/MgO) to 4.55x104 Ω.cm. The increased in the dielectric constant, with low tangent loss and high resistivity value suggests that 70°C was the favorable annealing temperature for PVDF/MgO film suitable for the application in electronic devices such as low frequency capacitor.