부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.commatsci.2006.09.004 Byline: C.C. dos Santos (a), J.P. Barbosa (a), M.A.B. dos Santos (a), F.A.M. Lira (a), F.J.B. Cardoso (a), J.C. Pinheiro (a), O. Treu Filho (b), R.T. Kondo (c) Keywords: Investigation of piezoelectricity; LaFeO.sub.3; Theoretical study; Ab initio study; Gaussian basis sets; GCHF method Abstract: In a previous report we studied theoretically the piezoelectric effect in barium titanate (BaTiO.sub.3) [O. Treu Filho, J.C. Pinheiro, R.T. Kondo, J. Mol. Struct. (THEOCHEM), 671 (2004) 71]. In this article we applied the Hartree-Fock (HF) theory in the investigation of piezoelectricity in LaFeO.sub.3. Initially, the generator coordinate HF (GCHF) method was used to build 22s14p, 30s19p13d, and 32s24p17d Gaussian basis sets for O(.sup.3P), Fe(.sup.5D), and La(.sup.2D) atoms. Then those basis sets were contracted to [7s6p], [13s8p6d], and [18s13p7d], respectively. The quality of the contracted basis sets in polyatomic calculations was evaluated through calculations of total and orbital energies (HOMO and HOMO-1) of.sup.2FeO.sup.1+ and.sup.1LaO.sup.1+. Finally, the contracted basis sets were supplemented with polarization and diffuse functions and used to investigate the piezoelectricity in LaFeO.sub.3. The calculated properties were dipole moment, total energy, and atomic charges and the analysis of those properties showed that covalent bonds constitute the electronic structure of [LaFeO.sub.3].sub.2 fragment. Therefore, it is reasonable to believe that LaFeO.sub.3 does not present piezoelectric properties. Author Affiliation: (a) Laboratorio de Quimica Teorica e Computacional, Departamento de Quimica, Centro de CiA*ncias Exatas e Naturais, Universidade Federal do Para, CP 101101, 66075-110 Belem, PA, AmazA[acute accent]nia, Brazil (b) Instituto de Quimica, UNESP, CP 335, Araraquara, SP, Brazil (c) Seccao de Tecnica de Suporte, Centro de Informatica de Sao Carlos, Universidade de Sao Paulo, 13560-970 Sao Carlos, SP, Brazil Article History: Received 11 November 2005; Revised 5 September 2006; Accepted 27 September 2006