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Structure variations within R Si 2 and R 2 Si 3 silicides. Part II. Structure driving factors
Author(s) -
Nentwich M.,
Zschornak M.,
Sonntag M.,
Gumeniuk R.,
Gemming S.,
Leisegang T.,
Meyer D. C.
Publication year - 2020
Publication title -
acta crystallographica section b
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.604
H-Index - 33
ISSN - 2052-5206
DOI - 10.1107/s2052520620003893
Subject(s) - lanthanide , electronic structure , density functional theory , crystal structure , transition metal , actinide , metal , lattice (music) , electronic band structure , crystallography , materials science , chemistry , computational chemistry , physics , condensed matter physics , inorganic chemistry , quantum mechanics , metallurgy , ion , biochemistry , acoustics , catalysis
To gain an overview of the various structure reports on R Si 2 and R 2 T Si 3 compounds ( R is a member of the Sc group, an alkaline earth, lanthanide or actinide metal, T is a transition metal), compositions, lattice parameters a and c , ratios c / a , formula units per unit cell, and structure types are summarized in extensive tables and the variations of these properties when varying the R or T elements are analyzed. Following the structural systematization given in Part I, Part II focuses on revealing the driving factors for certain structure types, in particular, the electronic structure. Here, concepts of different complexity are presented, including molecular orbital theory, the principle of hard and soft acids and bases, and a Bader analysis based on Density Functional Theory calculations for representatives of the reported structure types. The potential Si/ T ordering in different structures is discussed. Additionally, the influences from intrinsic and extrinsic properties ( e.g. elemental size and electronics as well as lattice parameters and structure type) are investigated on each other using correlation plots. Thermal treatment is identified as an important factor for the ordering of Si/ T atoms.