A note on the reactions in the Ti-Ge system

Abstract

Formations of germanides in thin films of the Ti-Ge system were investigated by XRD after furnace annealing for 1 hour. Ti6Ge5 seems to be the first phase formed while TiGe2 is the end phase with the lowest resistivity. The existence of the phase Ti5Ge3 was confirmed which forms at higher temperatures than Ti6Ge5. The presence of a thin TiO2 layer was observed by TEM. Which of the phase exists or is missed depends on composition of the constituents comprising the film, their thickness and temperature of reaction. Three phases are observed to coexist on the Ge substrate, which are Ti5Ge3, Ti6Ge5 and TiGe2. A schematic suggestion is presented for explaining the coexistence of two or more phases. The concept of formation and coexistence of two phases at lower temperatures is also proposed

Highly Stable Germanium Microparticle Anodes with a Hybrid Conductive Shell for High Volumetric and Fast Lithium Storage

“…Then, TiO 2 initiated the reduction by the Mg reductant while producing MCT (Ti 2 O 3 and TiO), called high titanium oxides (TiO x , 0.7 < x < 1.7) instead of complete Ti metal due to the energetically unfavorable reaction at a given condition (Figure c) . Ge and MCT additionally formed the Ti–Ge alloy interface (Ti 6 Ge 5 ) on the surface of the Ge core in the molten cluster by high pressure and heat of the exothermic reaction in the closed reactor (Figure d). , Consequently, the sequential metal oxide reduction allowed producing the HCG core–shell structure, which showed dense Ge microparticles in the core with the grown Ti-based shell by molten metal participation (Figures e, S1, and S2). A nanometer-thick Ti-derived shell (<100 nm) is displayed in Figure f where the structure consisted of MCT including Ti 2 O 3 and TiO crystal with the Ti 6 Ge 5 lattice fringe at the interface in HCG (Figure g).…”

Fermi-Level Unpinning Technique with Excellent Thermal Stability for n-Type Germanium

“…Moreover, the standard deviation ( s ) of log­( J R ) values, which indicates the variation of J R , increases remarkably, resulting in unstable and unreliable contact properties for both the M–S and the M–I–S structures (more details are in the Supporting Information). The increase of J R and s (log­( J R )) for the M–S structure results from the formation of Ti x Ge y alloys during the annealing process and the As + dopant segregation effect, , while the M–I–S structure returns to the form of the M–S structure. The Ti x Ge y alloy reduces the factor of series resistance through the contact because it provides smaller contact resistance at both metal/Ti x Ge y and Ti x Ge y /Ge interfaces than does the direct Ti contact.…”