Chemischer Transport fester Lösungen. 23 [1] Der Chemische Transport von Mischphasen im System MoS₂/MoSe₂, MoS₂/NbS₂, MoSe₂/NbSe₂ und NbS₂/NbSe₂

Abstract

Chemical Vapor Transport of Solid Solutions. 23 Chemical Vapor Transport of Mixed Phases in the System MoS2/MoSe2, MoS2/NbS2, MoSe2/NbSe2 and NbS2/NbSe2X‐ray powder investigations have shown that MoS2/MoSe2, MoS2/NbS2, MoSe2/NbSe2 and NbS2/NbSe2 form mixed crystals without a miscibility gap. The mixed crystals can be prepared by heating the Elements for some days in the presence of small amounts of iodine as well as by chemical vapour transport. In the systems NbS2/NbSe2 and MoS2/MoSe2 the vapor transport occurs congruently, in the systems NbS2/MoS2 and NbSe2/MoSe2 however a strong enrichment of Niobium has been observed during the transport process. Mass spectrometric investigations and thermochemical calculations have shown that the transport occurs via NbI4(g) and MoI3(g).

Ab initiostudy of bilateral doping within theMoS2-NbS2system

“…The data, obtained by optimizing the atomic positions simultaneously with the cell parameters, are presented in Fig. 5 and compared to the X-ray diffraction data available from the work of Hotje et al 19 The graph shows a good agreement between our theoretical results and the experimental data with a deviation of around 1% across the range of doping levels considered.…”

“…The experimental work of Hotje et al 19 has shown that the MoS 2 -NbS 2 alloy can be synthesized without any miscibility gap across the concentration range going from pure MoS 2 to pure NbS 2 . We have thus extended our investigation to higher doping levels up to a maximum of 25%.…”

“…Molybdenum disulphide (MoS 2 ) is widely used as catalyst in fuel desulphurization processes and tribological applications 13,14,15,16 and niobium disulphide (NbS 2 ) has attracted attention due to its optical, magnetic and superconductive properties. 1,4,17,18 The synthesis of mixed MoS 2 -NbS 2 with no miscibility gap has been reported 19 and for low level Nb-doping of MoS 2 particles, a semiconductor-metal transition has been observed.…”

THE SYSTEM Fe-Nb-S AND ITS GEOLOGICAL IMPLICATIONS

“…The best results ( Fig. 1) were obtained by in situ recrystallization in iodine vapor (Hinode et al 1987, Hotje & Binnewies 2005. All these experiments were performed without a temperature gradient.…”

Mismatch Strain versus Dangling Bonds: Formation of “Coin‐Roll Nanowires” by Stacking Nanosheets

“…These findings are consistent with strong deviations from Vegards law of the bulk phases in the system NbS 2 /MoS 2 . [17] A closer view of the layers in the HRTEM image reveals diffuse bending and kinking that increase along the edges of the stacks (Figure 4 b), while the whole structure remains straight. This result is surprising considering that kinks, interruption of layers, orthogonal faults, and low-contrast areas are observed.…”