نتایج جستجو برای: alkali metals
تعداد نتایج: 77771 فیلتر نتایج به سال:
Alkali metal cations can interact with Fe-N2 complexes, potentially enhancing back-bonding or influencing the geometry of the iron atom. These influences are relevant to large-scale N2 reduction by iron, such as in the FeMoco of nitrogenase and the alkali-promoted Haber-Bosch process. However, to our knowledge there have been no systematic studies of a large range of alkali metals regarding the...
The continuous reduction of magnetic units to ultrasmall length scales inspires efforts to look for a suitable means of controlling magnetic states. In this study, we show two surface charge alteration techniques for tuning the interlayer exchange coupling of ferromagnetic layers separated by paramagnetic spacers. Our ab initio study reveals that already a modest amount of extra charge can swit...
A new series of alkali-based complexes, AM@GenAu (AM = Li, Na, and K), have been theoretically designed and investigated by means of the density functional theory calculations. The geometric structures and electronic properties of the species are systematically analyzed. The adsorption of alkali metals maintains the structural framework of the gold-germanium bimetallic clusters, and the alkali ...
The recent discovery of superconductivity with a transition temperature (T(c)) at 18 K in K(x)picene has extended the possibility of high-T(c) superconductors in organic materials. Previous experience based on similar hydrocarbons, like alkali-metal doped phenanthrene, suggested that even higher transition temperatures might be achieved in alkali-metals or alkali-earth-metals doped such polycyc...
Up to date 12 complexes of triethanolamine with alkali, alkaline earth, lanthanide metals and hydrogen have been reponed. The synthesis and structure determination of these compounds is the subject of this review papacr. Moreover, the similarities and the differences of the complexes with respect to the metals and ligand are discussed.
We recognize eight types of ferroan granitoid that can be distinguished on the basis of major element chemistry.These include alkalic granitoids that may be metaluminous or peralkaline, alkali-calcic granitoids that may be metaluminous, peraluminous or peralkaline, calc-alkalic granitoids that may be metaluminous or peraluminous, and rare calcic ferroan granitoids. These granitoids may form by ...
Layered materials embrace rich intercalation reactions to accommodate high concentrations of foreign species within their structures, and find many applications spanning from energy storage, ion exchange to secondary batteries. Light alkali metals are generally most easily intercalated due to their light mass, high charge/volume ratio and in many cases strong reducing properties. An evolving ar...
At ambient conditions, lithium and sodium behave as free-electron metals and adopt highly symmetric close-packed structures. Under high pressure, however, these simple metals undergo a series of complex phase transitions to structures of lower symmetry, along with significant changes of their physical properties. In this review we provide a comprehensive description of these light alkali metals...
In recent years, the organometallic and coordination chemistry of the alkali and alkaline earth metals has experienced tremendous progress to tackle the needs of today’s society. Enhanced ecological awareness and global availability favor research on the chemistry of the essential s-block metals. Nowadays, the s-block metals are conquering new chemical fields based on sophisticated theoretical ...
The extended Hubbard Hamiltonian on a bcc lattice is studied at half-filling and for a finite hopping between next-nearest-neighbours, in mean-field approximation. An ionic insulating broken-symmetry phase is predicted for any hydrogenoid bcc solid in the density range 1.0 < r s < 2.6. The occurrence of an ionic phase would explain the failure to achieve hydrogen metallization at high pressures...
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