Calculating of the Unrelaxed Surface Energy of Spinel Ferrites

• Journal title : Korean Journal of Materials Research
• Volume 25, Issue 12,  2015, pp.713-718
• Publisher : The Materials Research Society of Korea
• DOI : 10.3740/MRSK.2015.25.12.713
Title & Authors
Calculating of the Unrelaxed Surface Energy of Spinel Ferrites
Shin, Hyung-Sup; Sohn, Jeongho;

Abstract
A new method is proposed for the calculation of the unrelaxed surface energy of spinel ferrite. The surface energy calculation consists of (1) setting the central and computational domains in the semi-infinite real lattice, having a specific surface, and having an infinite real lattice; (2) calculation of the lattice energies produced by the associated portion of each ion in the relative domain; and (3) dividing the difference between the semi-infinite lattice energy and the infinite lattice energy on the exposed surface area in the central domain. The surface energy was found to converge with a slight expansion of the domain in the real lattice. This method is superior to any other so far reported due to its simple concept and reduced computing burden. The unrelaxed surface energies of the (100), (110), and (111) of $\small{ZnFe_2O_4}$ and $\small{Fe_3O_4}$ were evaluated by using in the semi-infinite real lattices containing only one surface. For the normal spinel $\small{ZnFe_2O_4}$, the(100), which consisted of tetrahedral coordinated $\small{Zn^{2+}}$ was electrostatically the most stable surface. But, for the inverses pinel $\small{Fe_3O_4}$, the(111), which consisted of tetrahedral coordinated $\small{Fe^{3+}}$ and octahedral coordinated $\small{Fe^{2+}}$ was electrostatically the most stable surface.
Keywords
surface energy;real lattice;unrelaxed surface;lattice energy;spinel ferrite;
Language
Korean
Cited by
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