Origin of lowered magnetic moments in epitaxially strained thin films of multiferroic Bi${}_2$FeCrO${}_6$

Abstract

We have investigated the effect of epitaxial strain on the magnetic properties and $B$-site cation ordering in multiferroic Bi${}_2$FeCrO${}_6$ (001) thin films using a density-functional theory approach. We find that in thin films with rock-salt ordering of Fe and Cr the ground state is characterised by C-type anti-ferromagnetic (AFM) order. This is in contrast to the bulk form of the material which was predicted to be a ferrimagnet with G-type AFM order. Furthermore, the cation ordered thin-films undergo a transition with epitaxial strain from C to A-type AFM order. Other magnetic orders appear as thermally accessible excited states. We also find that $B$-site cation disordered structures are more stable in coherent epitaxial strains thereby explaining the lowered magnetic moments observed in these samples at room temperature. Strain varies both the sign as well as strength of the Fe-Cr superexchange coupling resulting in a very interesting phase diagram for Bi${}_2$FeCrO${}_6$ thin films.

References in corpus (9)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• A linear response approach to the calculation of the effective interaction parameters in the LDA+U method
• First principles study of the multiferroics BiFeO${}_3$, Bi${}_2$FeCrO${}_6$, and BiCrO${}_3$: Structure, polarization, and magnetic ordering temperature
• Spin Density Functional Based Search for Half-Metallic Antiferromagnets
• Ab-initio prediction of a new multiferroic with large polarization and magnetization
• First principles study of electronic and structural properties of CuO
• BaFe${}_2$Se${}_3$: a high $T_{\mathrm{C}}$ magnetic multiferroic with large ferrielectric polarization
• Epitaxial thin films of the multiferroic double perovskite Bi2FeCrO6 grown on (100)-oriented SrTiO3 substrates: Growth, characterization, and optimization
• Local Electronic and Magnetic Studies of an Artificial La2FeCrO6 Double Perovskite

Cited by in corpus (5)

• Electron-Hole Separation in Ferroelectric Oxides for Efficient Photovoltaic Responses
• Defect-induced modulation of magnetic, electronic and optical properties of double perovskite oxide La${}_2$CoMnO${}_6$
• Exploring the structural , electronic and magnetic properties of cation ordered 3d-5d double perovskite Bi${}_2$FeReO${}_6$ and Bi${}_2$FeIrO${}_6$ thin-films from first-principles
• Epitaxial strain control of hole-doping induced phases in a multiferroic Mott insulator Bi2FeCrO6
• Giant Ferrimagnetism and Polarization in a Mixed Metal Perovskite Metal-Organic Framework