Deynekoite, Ca9□Fe3+(PO4)7 (R3c, a = 10.3516(3)Å, c = 37.1599(17)Å, V = 3448.4(3)Å3 and Z = 6), a new mineral of the merrillite group was found in the contact facies of paralava of the Hatrurim Complex in the Daba-Siwaqa pyrometamorphic rock field, Jordan. The paralava, consisting of diopside, tridymite, anorthite, wollastonite and fluorapatite, is enriched in Fe-bearing phosphides and phosphates at the contact with the altered country rock. Cristobalite overgrowing tridymite has a fish-scales texture indicating that temperature of paralava could have reached 1500°C. Deynekoite with empirical formula (Ca8.90Na0.11K0.02)Σ9.03(Fe3+0.62Mg0.30Al0.05)Σ0.97P6.98V5+0.05O27.70(OH)0.30 forms transparent, light-yellow or light-brown grains up to 30–40 μm in size. Microhardness of deynekoite, VHN25 = 319(29) kg/mm2, corresponds to Mohs hardness = 4.5. Its density was calculated as 3.09 g⋅cm–3 on the basis of its empirical composition and structural data. Deynekoite is uniaxial (−), its refractive indices are ω = 1.658(3), ɛ = 1.652(3) (λ = 589 nm), and pleochroism is not observed. The formation of phosphides on the boundary of the paralava and country rock is connected with carbothermal reductive reactions and realised at temperatures above 1300°С. With decreasing temperature and increasing oxygen activity, phosphides are replaced by Fe2+-bearing phosphates. Deynekoite, which contains Fe3+ (substituting for Fe2+-phosphates) and a small amount of water, formed at temperatures of 600–800°C.

This paper presents 66 radiocarbon (14C) dates obtained at 33 key sites from the Polish part of the European Sand Belt. These calibrated dating results were compared to 34 high-resolution 14C dates obtained from a fluvial-aeolian sediments to identify pedogenic phases from the late Pleniglacial interval to the early Holocene. These identified pedogenic phases were correlated with Greenland ice-core records, revealing high sensitivity of the fluvio-aeolian paleoenvironment to climate changes. Two pedogenic phases were identified from the late Pleniglacial interval (Greenland Stadial GS-2.1b and GS-2.1a), three from the Bølling-Allerød interstadial (Greenland Stadial GI-1), one from the late Allerød–Younger Dryas boundary, and at least one from the Younger Dryas. The ages of these pedogenic phases reveal a distinct delay of 50–100 calendar years after the onset of cool climate conditions during GI-1, reflecting gradual withdrawal of vegetation. Soil horizons from the early Holocene do not show any clear relation with climate change, where breaks in soil formation were caused by local factors such as human activity.

In this work, the mechanical properties of cubic silicon carbide are explored through the analysis of the static and dynamic behavior of 3C-SiC cantilevers. The investigated structures were micro-machined using Inductively Coupled Plasma (ICP) etching of thin 3C-SiC films grown on silicon. The aim was to evaluate the influence of some basic parameters (film orientation, film thickness, defect density) on the mechanical properties of the material.

X-Ray Diffraction was used to evaluate the crystalline quality of the epilayers. Scanning Electron Microscopy observations of static cantilever deflection highlight the major difference between the stress states of (100) and (111) oriented layers for which the intrinsic stresses are of opposite signs. The cantilever deflection is highly dependent on the film thickness, as stated for (100) oriented epilayers. The lowest deflection is obtained for the thickest layer. The Young's modulus of 3C-SiC is calculated from the resonance frequency of clamped-free cantilevers, measured by laser Doppler vibrometry. The relatively low and orientation independent value of Young's modulus (~350GPa) found on the samples is probably associated with the high defect density usually observed in very thin 3C-SiC films grown on Si.

We present an experimental study of asymmetric wafer deformation for 3C-SiC layers grown on deliberately misorientated silicon substrates. An asymmetric curvature has been observed both on (100) and (111) oriented layers. In this work we focus on the (100) oriented samples. The curvature of the wafers is studied as a function of wafer thickness and offcut angle. We look for the correlations between the observed asymmetric strain relaxation and the layer morphology and microstructure. We claim that different defect pattern, measured along [110] and [1-10] direction can be at the origin of almost complete relaxation of mismatch strain along the offcut direction.

In this work, non-intentionally doped 3C-SiC epilayers were implanted using phosphorus at different energies and subsequently annealed at temperatures between 1100°C and 1350°C in order to form n+ implanted layers. Different techniques such as Fourier Transformed InfraRed spectroscopy (FTIR) and Secondary Ion Mass Spectroscopy (SIMS) were used to characterize implanted 3C-SiC epilayers after the different annealing steps. Successively, metal layers were sputtered in order to form the contacts. The specific contact resistance (ñC) was determined by using circular Transfer Length Method (c-TLM) patterns. Specific contact resistance values were investigated as a function of doping and contact annealing conditions and compared to those obtained for highly doped 3C-SiC epilayers. As expected, ñC value is highly sensitive to post-implantation annealing and metal contact annealing. This work demonstrates that low resistance values can be achieved using phosphorus implantation and, hence, enabling device processing.

In this work, we study cubic SiC/Si (111) templates as an alternative for growing GaN on silicon. We first developed the epitaxial growth of 3C-SiC films on 50mm Si(111) substrates using chemical vapor deposition. Then, AlGaN/GaN high electron mobility transistors were grown by molecular beam epitaxy on these templates. Both the structural quality and the behavior of transistors realized on these structures show the feasibility of this approach.

Microstructure and thermal stability of ZrN/ZrB2 bilayer deposited on GaN have been studied using transmission electron microscopy methods (TEM) and secondary ion mass spectrometry (SIMS). It has been demonstrated that annealing of the contact structure at 1100°C in N2 atmosphere does not lead to any observable metal/semiconductor interaction. In contrast, a failure of the integrity of ZrN/ZrB2 metallization at 800°C, when the heat treatment is performed in O2 ambient has been observed.