The bonding character was determined from the absorption spectra band positions by calculating the nephelauxetic ratio (β) and bonding parameters (δ) to assess the ionic or covalent nature of the bonds. The direct optical band gap energy decreases from 3.214 to 3.173eV, while the indirect ...
Furthermore, the calculated results of the density of states and Mulliken population indicate that the interactions among atoms are both ionic and covalent bonding in strontianite. (C) 2016 Elsevier Ltd. All rights reserved.Hu, ZuoweiLi, YunZhang, ChuanyuAo, Bingyun...
SrTiO3 is a well-known ABO3-type model perovskite with ideal cubic structure (geometric tolerance factor ~1) at room temperature [12], possessing mixed ionic-covalent bonding properties [13], which confer excellent electronic features. Having a closer look at its unit cell, along the ...