First-principles studies on mechanical, electronic, magnetic and optical properties of new multiferroic members BiLaFe2O6 and Bi2FeMnO6: Originated from BiFeO3

Recently multiferroic materials have attract great interest for the applications on memorial, spintronic and magneto-electric sensor devices for their spontaneous magneto-electric coupling properties. Research and development of the various kinds of multiferroics are indispensable factor for a new generation multifunctional materials. In this research, mechanical, electronic, magnetic and nonlinear optical properties of La modified BiLaFe2O6 (BLFO) and Mn modified Bi2FeMnO6 (BFMO) were studied as new members of multiferroic BiFeO3 (BFO) series by first-principles calculations, and compared with the pure BFO to discover the optimized properties. Our results show that BLFO and BFMO have good mechanical stability as revealed by elastic constants that satisfy the stability criteria. All these compounds exhibit anisotropic and ductile nature. The enhanced properties by La and Mn substitution, such as increased hardness, improved magnetism, decreased band gap and comparable second harmonic generation responses reveal that the new multiferroic members of BLFO and BFMO would get wider application than their BFO counterpart. Our study is expected to providing an appropriate mechanical reference data as guidance for engineering of high efficiency multifunctional devices with the BFO series. Multiferroic materials BFO, BLFO and BFMO were investigated with the aid of first principles studies. Results indicate that the BFO, BLFO and BFMO are mechanically stable, and exhibit anisotropic and ductile nature. BLFO and BFMO possess narrow band gap than BFO, density of state and spin density polarization results show that the BLFO and BFMO have good magnetic property than the BFO. The angular-dependent SHG responses clearly show that the BFO, BLFO and BFMO exhibit highly polarized SHG response. In conclusion, new multiferroic members BLFO and BFMO would get wider application than their BFO counterpart. [Display omitted] •BiLaFe2O6, Bi2FeMnO6 and BiFeO3 exhibit anisotropic and ductile nature with a mechanically stable phase.•BiLaFe2O6 and Bi2FeMnO6 show decreased band gap and increased magnetism than the pristine BiFeO3.•All BiLaFe2O6, Bi2FeMnO6 and BiFeO3 compounds possess high second harmonic generation response.