La3Si6N11
نویسندگان
چکیده
Colorless transparent single crystals of trilanthanum hexa-silicon undeca-nitro-gen, La3Si6N11, were prepared at 0.85 MPa of N2 and 2273 K. The title compound is isotypic with Sm3Si6N11. Silicon-centered nitro-gen tetra-hedra form a three-dimensional network structure by sharing their corners. Layers of one type of SiN4 tetra-hedra and slabs composed of the two different La(3+) cations and the other type of SiN4 tetra-hedra are alternately stacked along the c axis of the tetra-gonal unit cell. The site symmetries of the two La(3+) cations are are ..m and 4.., respectively.
منابع مشابه
First-principles Study of Ce doped Lanthanum Silicate Nitride Phosphors: Neutral Excitation, Stokes Shift and Luminescent Center Identification
We study from first principles two lanthanum silicate nitride compounds, LaSi3N5 and La3Si6N11, pristine as well as doped with Ce ion, in view of explaining their different emission color, and characterising the luminescent center. The electronic structures of the two undoped hosts are similar, and do not give a hint to quantitatively describe such difference. The 4f → 5d neutral excitation of ...
متن کاملGains from diversification on convex combinations: A majorization and stochastic dominance approach
By incorporating both majorization theory and stochastic dominance theory, this paper presents a general theory and a unifying framework for determining the diversification preferences of risk-averse investors and conditions under which they would unanimously judge a particular asset to be superior. In particular, we develop a theory for comparing the preferences of different convex combination...
متن کاملImproved immunogenicity of tetanus toxoid by Brucella abortus S19 LPS adjuvant.
BACKGROUND Adjuvants are used to increase the immunogenicity of new generation vaccines, especially those based on recombinant proteins. Despite immunostimulatory properties, the use of bacterial lipopolysaccharide (LPS) as an adjuvant has been hampered due to its toxicity and pyrogenicity. Brucella abortus LPS is less toxic and has no pyrogenic properties compared to LPS from other gram negati...
متن کاملSteady electrodiffusion in hydrogel-colloid composites: macroscale properties from microscale electrokinetics.
A rigorous microscale electrokinetic model for hydrogel-colloid composites is adopted to compute macroscale profiles of electrolyte concentration, electrostatic potential, and hydrostatic pressure across membranes that separate electrolytes with different concentrations. The membranes are uncharged polymeric hydrogels in which charged spherical colloidal particles are immobilized and randomly d...
متن کاملPerturbative Analysis of Dynamical Localisation
In this paper we extend previous results on convergent perturbative solutions of the Schrödinger equation of a class of periodically timedependent two-level systems. The situation treated here is particularly suited for the investigation of two-level systems exhibiting the phenomenon of (approximate) dynamical localisation. We also present a convergent perturbative expansion for the secular fre...
متن کامل