Multiferroicity in layered perovskites

MACCIONI, MARIA BARBARA;SCARROZZA M;FIORENTINI, VINCENZO

2013-01-01

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Abstract

We have explored via rst-principles calculations two possible ways to achieve mul- tiferroicity in a layered-perovskite \topological" [1] ferroelectric La2Ti2O7 (LTO). We nd that (i) low-concentration substitution of Ti by V produces robust uni- directional ferromagnetic (FM) order, resulting in a small-gap proper multiferroic material; (ii) the isovalent substitution of Mn for Ti produces multiferroicity with weak FM order due to canting of AF Mn spins, and large magnetoelectric coupling. First-principles calculations are performed in the generalized gradient approximation to density functional theory (DFT), as implemented in VASP [2], and electron-ion interaction is described within the PAW scheme in both cases.