Enhancement of ferromagnetism in a multiferroic La–Co co-doped BiFeO₃ thin films

Abstract

BiFeO3 (BFO) based materials have attracted much attention due to its room-temperature multiferroic properties and ultrahigh ferroelectric polarization. La and Co co-doped BiFeO3 (BLFCO) thin films were fabricated on Pt (111)/Ti/SiO2/Si substrate buffered by Nb (0.7 wt. %)doped SrTiO3 (NSTO) via the pulsed laser deposition. The experiments revealed that the film deposited at 0.2 Pa was predominant orientation of BFO (111), and its surface root-mean-square roughness was 0.96 nm. The saturation magnetization of the film reached 25.3 emu/cm3, which was an order of magnitude higher than that of pure BFO film, and it was attibuted to the predominant orientation and small grain size of BLFCO films. These results are helpful to furtherly improve the performance of BFO multi-functional devices.

Room temperature ferroelectricity and ferromagnetism in Ni-substituted Bi5Ti3FeO15

“…The (Bi 2 O 2 ) 2+ layers play key roles in both space-charge compensation and insulation, which are expected to reduce the leakage current. The BTF is considered to be a combination of ferroelectric Bi 4 Ti 3 O 12 and multiferroic BiFeO 3 , herein the Bi 4 Ti 3 O 12 is a typical ferroelectric compound and well-known fatigue-free ferroelectric material by lanthanide substitution at the A-site [14][15][16][17], whereas BiFeO 3 is the only well-studied single-phase multiferroic material that exhibits both ferroelectric and antiferromagnetic orders [18][19][20][21][22][23][24]. However, the intrinsic character of the antiferromagnetic state of the BTF along with a low Néel temperature (T N ) limits its application prospects [25][26][27], therefore; it is highly expected that both ferroelectric and ferromagnetic orders can coexist in the BTF.…”