First-principles studies of the magnetic structure and exchange interactions in the frustrated multiferroic YMnO3

• Published in: Journal of magnetism and magnetic materials Vol. 321; no. 9; pp. 1260 - 1265
• Main Authors: Zhong, Chonggui, Jiang, Xuefang, Yu, Hailin, Jiang, Qing, Fang, Jinghuai, Li, Zhenya
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier 01.05.2009
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Electron density of states and band structure of crystalline solids; Electron states; Exact sciences and technology; Ferroelectricity and antiferroelectricity; Magnetic properties and materials; Other inorganic compounds; Physics; Spin arrangements in magnetically ordered materials (including neutron and spin-polarized electron studies, synchrotron-source x-ray scattering, etc.); 71.27.+a; Total energy; Density of states; Noncollinear magnetism; Antiferromagnetic materials; Heisenberg model; 75.50.Ee; 71.70.Gm; Electronic density of states; Density function theory; Ferroic material; Energy gap; Electronic structure; Ferroelectricity; Triangular lattices; Yttrium Manganites; Exchange interaction; Density functional method; Magnetic structure; Generalized gradient approximation; Frustration; Exchange interactions; 75.30.Et
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2008.11.005

The electronic structure, magnetism and spin-exchange interactions of a frustrated antiferromagnet YMnO3 have been studied by the density functional theory (DFT) within the generalized gradient approximation (GGA) with the non-collinear magnetic structure calculations performed. The calculations show that triangular spin frustration plays an important role in the formation of band-gap, the decrease in total energy and the inducement of ferroelectric distortion in multiferroic YMnO3. The total energy analyses of the different spin configurations show that the magnetic structure with an intraplane frustrated antiferromagnetic (AFM) coupling between nearest-neighbor Mn spins at the edge sharing triangular network and an interplane AFM spin coupling is preferred. We have also estimated the values of exchange integrals by mapping the calculated total energies onto the Heisenberg spin model. The calculated results are consistent with previous experimental estimations.