Multiferroic properties of neodymium and cobalt co-doped four-layer Aurivillius compounds

Single-phase multiferroic materials have attracted much attention in recent years due to their rich fundamental physics and great application potential^[1]. In the last few years, the bismuth-based Aurivillius phase compound, which is formed by stacking fluorite-like (Bi₂O₂)²⁺ layers and per-oskite-like (A_n-1B_nO_3n+1)^2-, is one of the most promising candidates of single-phase multiferroic materials by doping magnetic cations at B site^[2]. Recently, co-doped Aurivillius compounds have been reported to present an enhanced ferroelectric or ferromagnetic properties^[3].