Synthesis and characterization of titanium dioxide doped nickel oxide dielectric materials

Nickel oxide (NiO) belongs to the transition metal oxide family, having good dielectric constantwith the range of 103 – 105, but it has high dielectric loss. In this research, the effect of titaniumdioxide (TiO2) addition into NiO was investigated. Generally, TiO2 was used in the application ofelectrical ceramic, catalysts, electric conductors and chemical intermediates. Ni1-xTixO1+x wasprepared via solid-state reaction method with 6 different TiO2 compositions. The preparation startedwith the powder mixing process for 24 hours and followed by calcination process at 950 °C for 4hours. Then, the calcined powders were compacted into 6 mm pellet shape under pressure of 250MPa pressure. Three pellets were made for each TiO2 composition. Those pellets were sintered at1250 °C for 5 hours. XRD results showed that pure NiO at 0.01 and 0.02 mole % of TiO2compositions produced single NiO crystalline phase, while 0.03, 0.05 and 0.10 mol % of TiO2showed the TiO2, instead of NiO phases. SEM analysis showed that increasing TiO2 concentrationmake the grain size increase, with 0.02 mole % of TiO2 gave the largest grain size, shows that 0.02mole % is the optimum TiO2 concentration for grain size enlargement. Furthermore, the bulkdensity of Ni1xTixO1+xpellet was reduces at higher TiO2 concentration. In dielectric test, the additionof 0.03 mole % of TiO2 gave the highest dielectric constant with value of 4.51 x 1014 and 0.05 mole% of TiO2 gives the result of lowest dielectric loss (0.53).

Comparative assessment of the qualities of commercial and synthetic transformer oils

. Petroleum transformer oils previously produced in the USSR met the requirements of ГОСТ 982-80. Balakhany oil and Dossor low-paraffin oil of the Emben field were the raw materials for obtaining transformer oil. The composition of transformer oils is taken into account when choosing raw materials and their regeneration. Т-1500у – transformer oil of improved quality, is used in electrical equipment up to 500 kV and up to 750 kV. ГК oil is a hydrocracking transformer oil, used in voltages up to 1150 kV, contains ionol. Тсп is oil from West Siberian oils, used up to 220 kV. This oil is of relatively low quality, characterized by a high sulfur content, low oxidation stability, and high dielectric loss tg. In the Institute of Petrochemical Processes of ANAS, research has been carried out on the selective purification of transformer oil distillate from Balakhany oil using a new highly effective solvent – ionic liquid (IL) – a quaternary ammonium salt of formic acid and a number of amines – morpholine, aniline or di-, triethylamines. The optimal conditions for the selective purification of the distillate have been developed. Due to the shortage of high-quality transformer oils, as well as the high cost, in recent years, oils have been imported from Sweden and Austria. An ionic liquid as a solvent is highly selective and selective. The analysis of the extract from selective purification showed that it does not contain naphthene-paraffins, the content of aromatic hydrocarbons in the extract is 65%, and when purified with furfural it is 40.8%. The ionic liquid is environmentally friendly.

Efficient Electromagnetic Wave Absorption of Porous CoO–Co@RGO Composites with Optimized Impedance Matching Derived from Metal-Organic Frameworks

In this study, we have successfully synthesized porous CoO–Co@RGO composites using GO and Co-based metal-organic frameworks (MOFs) as precursors. Due to particular structures and advantageous characteristics, the synthesized porous CoO–Co@RGO composites exhibit outstanding electromagnetic (EM) wave absorbing properties with a filler loading of 10[Formula: see text]wt.% in wax matrix. The maximum reflection loss (RL) of the prepared porous CoO–Co@RGO was [Formula: see text][Formula: see text]dB with 2.1[Formula: see text]mm thickness, and the effective absorption bandwidth as wide as 6.24[Formula: see text]GHz (11.76–18[Formula: see text]GHz), which covers the full Ku-band. Remarkably, the achieved all values of[Formula: see text]RL were under [Formula: see text][Formula: see text]dB with 1.0–5.0[Formula: see text]mm thickness, the corresponding to bandwidth range can be tuned to 13.84[Formula: see text]GHz (4.16–18[Formula: see text]GHz). The superior absorbing performance is attributed to suitable magnetic loss, high dielectric loss and large attenuation mainly caused by conduction loss and polarization relaxation.

2D MoS2/graphene composites with excellent full Ku band microwave absorption

2D MoS2/graphene composites were proved to be promising full Ku band MA materials due to their superb high dielectric loss.

Preparation and unique dielectric properties of nanoporous materials with well-controlled closed-nanopores

Although general porous materials have a low dielectric constant, their uncontrollable opened porous structure results in high dielectric loss and poor barrier properties, thus limiting their application as interconnect dielectrics.

Dielectric Properties of Li2CO3 Doped Nio Measured at High Frequency

NiO-based ceramic has shown high dielectric constant with 103-105, as well as high dielectric loss. Previous studies showed that doping with monovalent cations can cause a considerable decrease in dielectric loss. In this research, the effect of Lithium carbonate (Li2CO3) dopant on NiO was investigated. The electroceramic of LixNi1-xO were prepared by using solid state reaction method. The mixture of Li+ and NiO were ball milled for 24 hours. The samples were calcined at 800oC for 6 hours, pressed into pellet shape at 750 MPa and sintered at 1200°C for 10 hours. The sintered pellets were subjected to XRD, SEM, density testing and Impedance analyzer. XRD result shows the single phase formation of LixNi1-xO. The grain becomes larger with the increament of Li+ mole %. The dielectric constant of LixNi1-xO decrease with the increasing frequency. The highest dielectric constant was observed in x= 0.03 with 5210 at frequency range of 1GHz to 1MHz.