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The quest for effective thermal management solutions for microelectronic devices, catering to the escalating heat flows, necessitates innovative strategies. The significance of thermal interface materials, especially thermal greases, in minimizing thermal resistance within the "microelectronic device—heat-dissipating element" interface, has been widely acknowledged across industries such as microelectronics, aviation, and space engineering. Despite the promising reported values, a crucial consideration entails the method of ascertaining effective thermal conductivity, necessitating measurements in bulk samples to ensure accurate representations. Graphite, owing to its commercial accessibility and commendable thermal conductivity, emerges as a standout candidate for composite material development, as demonstrated in recent research. We observed that the use of graphite-based fillers, particularly in the form of well-crystallized graphite particles, effectively reduced processor temperatures and enhanced effective thermal conductivity, outperforming industrially utilized thermal greases. Our findings accentuate the potential of these materials in contributing to the development of cutting-edge composite materials for microelectronics, highlighting their high prospects for future applications in high-performance devices. [ABSTRACT FROM AUTHOR]

The interaction of gaseous AlF with SiO gave Si dendrites and whiskers as a result of the transport chemical reaction of Al, AlF3 and SiO2 starting materials. The reaction yield depends on temperature, transport gas flow-rate, reactor chamber pressure and molar ratio of the initial compounds. The thermodynamic simulation of the processes in reaction chamber was performed by the HSC Chemistry program using HSC-Reaction and HSC-Gibbs modules. Reaction products were characterized by X-ray powder diffraction and scanning electron microscopy. Obtained silicon crystallizes as dendrites and whiskers with diameters ranging from 100 nm to 24 μm. The data obtained demonstrates the potential of the proposed technology for the production of Si anode material. [ABSTRACT FROM AUTHOR]

The rock-salt ordered A2CuWO6 (A = Sr, Ba) with I4/m space group and disordered SrCu0.5M0.5O3−δ (M = Ta, Nb) with Pm3m space group perovskites were successfully obtained via a solid-state reaction route. Heat treatment of Ba2CuWO6 over 900 °C in air leads to phase decomposition to the barium tungstate and copper oxide. Thermogravimetric measurements reveal the strong stoichiometric oxygen content and specific oxygen capacity (ΔWo) exceeding 2.5% for Ba2CuWO6. At the same time, oxygen content reveals Cu3+ content in SrCu0.5Ta0.5O3−δ. Under the following reoxidation of Ba2CuWO6, step-like behavior in weight changes was observed, corresponding to possible Cu+ ion formation at 900 °C; in contrast, no similar effect was detected for M5+ cations. The yellow color of Ba2CuWO6 enables to measure the band gap 2.59 eV. SrCu0.5Ta0.5O3−δ due to high oxygen valance concentration has a low thermal conductivity 1.28 W·m−1·K−1 in the temperature range 25–400 °C. [ABSTRACT FROM AUTHOR]

Nanotubular titanium oxide is widely known as a prospective semiconductor photocatalyst for the process of water splitting. Its photoelectrochemical (PEC) efficiency can be improved by doping with 3d metal. In this work, the synthesis of nanotubular titanium oxide (NTO) was carried out by anodizing titanium substrates using two doping techniques. First, Ni-doped TiO2 was obtained by immersion in Ni salt solution; second, an ethylene glycol-based fluoride electrolyte containing Ni2+ ions solution was used. The obtained samples were analyzed using SEM, XRD, and photoelectrochemical methods. The produced Ni-doped NTO exhibited photocatalytic activity twice as high as that of nondoped NTO. Additionally, it was found that the immersion technique initiated a shift of the incident photon to converted electron (IPCE) spectra to the visible part of the spectrum. [ABSTRACT FROM AUTHOR]

The microstructure of Basalt matrix composite materials produced by pressureless aluminum melt infiltration at 950 °C was investigated. It is established that uniform elements distribution is observed within the whole sample depth. Interestingly, aluminum content variation considerably matches the hardness of the sample profile that is connected with alumina phase presence. Sample color changes during temperature treatment due to phase transitions were observed. The appearance of the hematite (Fe2O3) phase makes the initial preform red. After infiltration by molten aluminum, oxygen-deficient alumosilicate phases turn the color black. The infiltration process decreases the porosity insufficiently due to a partial reduction of alumosilicates by molten Al and the hardness of infiltrated samples was only 2.2 GPa. Nevertheless, a huge thermal conductivity rise from 1.45 to 4.53 W/(m·K), along with a fracture toughness increase, makes the produced composite a prospective wear-resistant material. Moreover, the developed low-temperature production technology allows for obtaining a very cost-effective material. [ABSTRACT FROM AUTHOR]

New polymer thermal interface materials (TIM) with high thermal conductivity values are very interesting for high-end microelectronics. Nevertheless, most polymer composite materials do not have desirable properties due to the isolating distribution of filler particles in the matrix. It is assumed that thermal greases with hybrid fillers can form a densely packed percolate structure, leading to considerable thermal conductivity enhancement. The results demonstrate that the addition of a second filler allows the thermal conductivity of the specimen and the volume fraction to increase, which provides the formation of various packaging types within composite material production. The highest thermal conductivity value, 3.02 W/(m K), is achieved for the grease AlN:C (1:2 mass ratio). The simulation and operational bench test of a CPU under thermal loads show a considerable working temperature decrease for AlN and AlN:Al (4:1 mass ratio) greases to 46°C and 47°C, respectively, 29.2% lower than for greases with a graphite or silicon carbide filler. [ABSTRACT FROM AUTHOR]