We present a novel approach to reduce the thermal conductivity ($\kappa$) in thermoelectric composite materials using acoustic impedance mismatch and Debye model. Also, correlation between interface resistance (R$_{int}$) particle size of dispersed phase on k is discussed. In particular, $\kappa$ an oxide which consists natural superlattice Aurivillius (SrBi$_4$Ti$_4$O$_{15}$) as matrix perovsk...

Two conventionally solidified Al-0.2Ti alloys (with 0.18 and 0.22 at. pct Ti) exhibit no hardening after aging up to 3200 hours at 375 C or 425 C. This is due to the absence of Al3Ti precipitation, as confirmed by electron microscopy and electrical conductivity measurements. By contrast, an Al-0.2Zr alloy (with 0.19 at. pct Zr) displays strong age hardening at both temperatures due to precipita...

The structure, elastic properties and electronic structure of Ti-Al intermetallics including Ti3Al (space group P63/mmc), TiAl I4/mmm) TiAl3 P4/mmm) are systematically studied by first-principles calculations. results show that can exist stably whether Cr replaces Ti or Al. ductility the alloy cannot be improved when is replaced in Cr-doped TiAl3. However, it Al, has better ductility. In Ti3Al,...

We address the long-standing question of nature oxygen vacancies in strontium titanate, using a combination density functional theory and dynamical mean-field (DFT+DMFT) to investigate particular effect vacancy-site correlations on electronic properties. Our approach uses minimal low-energy subspace including Ti-$t_{2g}$ orbitals plus an additional vacancy-centered Wannier function, provides in...

Abstract: Production of titanium aluminides in TiO2-Al-Ca system has been investigated. For this purpose, different compositions of raw materials were studied in a special reaction vessel. In a special case, the non-completed reaction of TiO2 with Al and Ca resulted in the production of granulates of titanium aluminides especially Ti3Al and other Ti – Al phases as the metallic product and C...

The studies are focused on the properties of multilayer composite coating based (Ti,Y,Al)N system with high content yttrium (about 40 at.%) (Y). hardness and elastic modulus were defined, resistance to fracture was studied during scratch testing. Two cubic solid solutions (fcc phases), including c-(Ti,Y,Al)N c-(Y,Ti,Al)N, formed in coating. investigation wear (Ti,Y,Al)N-coated tools turning ste...

The two-dimensional electron gas (2DEG) formed at the n-type (LaO)(+1)/(TiO2)(0) interface in the polar/nonpolar LaAlO3/SrTiO3 (LAO/STO) heterostructure (HS) has emerged as a prominent research area because of its great potential for nanoelectronic applications. Due to its practical implementation in devices, desired physical properties such as high charge carrier density and mobility are vital...