In this work, we propose a method to improve electro-optical and structural parameters of light-absorbing kesterite materials. It relies on the application of weak power hydrogen plasma discharges using electromagnetic field of radio frequency range, which improves homogeneity of the samples. The method allows to reduce strain of light absorbers and is suitable for designing solar cells based o...

Group 14 elements (C, Si, and Ge) exist as various stable and metastable allotropes, some of which have been widely applied in industry. The discovery of new allotropes of these elements has long attracted considerable attention; however, the search is far from complete. Here we computationally discovered a tetragonal allotrope (12 atoms/cell, named T12) commonly found in C, Si, and Ge through ...

The thermochemlcal stablllty of fast oxygen ion conductlng yttria stabillzed blsmuthoxlde (YSB) r solld solutlons containing 22.0 32.5 mol% of yttrla was investigated. It was shown that In the temperature range between 650 740 C the stabilized cublc ~ -phase contalnlng less than 31.8 mol% of yttrla ls not stable durlng long term annealing treatments (>~500 hours). During annealing at 650 C a sl...

An yttria stabilised zirconia which exhibits a coreshell microstructure was investigated as a method to produce a zirconia with high ionic conductivity and improved thermal shock resistance. Zirconia grains consist of an outer shell of tetragonal zirconia with an inner core of monoclinic phase zirconia. Impedance spectroscopy was used to identify the e€ect of processing conditions on the grain ...

We have studied the surfaces of zirconia (ZrO2) by first-principles calculations using density functional theory. We predict surface energies and relaxations for the principal surfaces of different bulk phases of zirconia. We find that the stoichiometric tetragonal~111! and monoclinic~1̄11! are the most stable surfaces. We find a strong linear correlation between surface energies before and afte...

We present the results of a plane wave based density functional study of the structure and properties of tetragonal zirconia in the range of pressures from 0 to 50 GPa. We predict a transition to a fluorite-type cubic structure at 37 GPa which is likely to be of a soft mode origin and is accompanied by a power law decrease of the frequency of the Raman-active A(1g) mode. A detailed study of the...

Degradation of yttria-stabilized zirconia dental implants abutments due to the tetragonal to monoclinic phase transformation was studied in detail by microstructural characterization using Electron Back Scatter Diffraction (EBSD). The amount and distribution of the monoclinic phase, the grain-size distribution and crystallographic orientations between tetragonal and monoclinic crystals in 3 mol...

Nanosized sulfated zirconia with Brønsted acidic sites has been prepared by a simple calcination in the absence of any solvent. XRD patterns reveal that the sulfated zirconia mainly consists of tetragonal crystalline zirconia with average size of about 7 nm, which is further confirmed by TEM images. N2 adsorption data show that the nanosized sulfated zirconia has high surface area (165-193 m2/g...

Yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) have proved to be important structural ceramics. High strength and fracture toughness make them attractive candidates for a number of demanding applications. It was established that these advantageous properties are strongly influenced by the ceramic microstructure [1]. The relationships between microstructure and mechanical properties ...