Unusual continuous dual absorption peaks in Ca-doped BiFeO₃nanostructures for broadened microwave absorption

Abstract

Electromagnetic absorption materials have received increasing attention owing to their wide applications in aerospace, communication and the electronics industry, and multiferroic materials with both polarization and magnetic properties are considered promising ceramics for microwave absorption application. However, the insufficient absorption intensity coupled with the narrow effective absorption bandwidth has limited the development of high-performance multiferroic materials for practical microwave absorption. To address such issues, in the present work, we utilize interfacial engineering in BiFeO3 nanoparticles via Ca doping, with the purpose of tailoring the phase boundary. Upon Ca-substitution, the co-existence of both R3c and P4mm phases has been confirmed to massively enhance both dielectric and magnetic properties via manipulating the phase boundary and the destruction of the spiral spin structure. Unlike the commonly reported magnetic/dielectric hybrid microwave absorption composites, Bi0.95Ca0.05FeO3 has been found to deliver unusual continuous dual absorption peaks at a small thickness (1.56 mm), which has remarkably broadened the effective absorption bandwidth (8.7-12.1 GHz). The fundamental mechanisms based on the phase boundary engineering have been discussed, suggesting a novel platform for designing advanced multiferroic materials with wide applications.

Tailoring the Electrochemical Behaviors of Bismuth Ferrite Using Ca Ion Doping

“…HRTEM was utilized to characterize the microstructure of the neat BFO, BFO-5%Ca, BFO-10%Ca, and BFO-20%Ca samples, as shown in Figures 3a-d. In particular, the spacing of the adjacent lattice fringes in the neat BFO is about 0.284 and 0.399 nm (Figure 3a), in accordance with the (104) and 012planes of pure BFO (Li et al, 2016). The TEM images of highresolution images along [110] zone axis are shown to confirm small changes in the crystal structure (Figures 3e-h) (Gao et al, 2018).…”

Broadening Electromagnetic Absorption Bandwidth: Design from Microscopic Dielectric‐Magnetic Coupled Absorbers to Macroscopic Patterns

“…[20,30,31] Initially, the commercial graphite sample 500 mg was treated in mixing solution of water and EtOH for stirring and sonication for 20 h. Upon the samples were dried, the as-treated powders were then added into an acidic mixing solution (HNO 3 :H 2 SO 4 ¼ 1:3 in volume ratio), followed by sonication for 2 days. Until the liquid exfoliation was completed, the mixture was then transferred to 3 L water, followed by washing abundant water.…”

Fe3O4 nanoparticles decorated on a CuS platelet-based sphere: a popcorn chicken-like heterostructure as an ideal material against electromagnetic pollution

“…[1][2][3][4][5] Consequently, developing electromagnetic absorption (EA) materials is an urgent countermeasure, which is required to deal with the various harmful effects of electromagnetic irradiation on humans and on the environment. These materials can dissipate or transform the energy of electromagnetic radiation into thermal energy.…”