Effect of corona treatment on magnetic properties of nanoscaled multiferroic films BiFeO_3, (BiLa)FeO_3 and (BiNd)FeO_3

摘要

Multiferroic films of BiFeO_3, (BiLa)FeO_3 and (BiNd)FeO_3 with various concentration of ions of Bi, La and Nd in dodecahedral sublattice were fabricated on monocrystalline substrates of (001) SrTiO_3, (100) MgO and (100) Al_2O_3 by a number of technological methods. The film thickness varied in the range of 30-300 nm. Doping BiFeO_3 films by rear earth ions La(Nd) increases both the magnetisation saturation and Neel temperature, as well as magnetoelectric effects, which is explained by increase in magnetic crystal anisotropy and suppression of spatially modulated magnetic structure. The corona discharge treatment resulted in a substantial growth of the magnetisation saturation up to 35% whereas the changes in the Neel temperature were not noticeable. This is explained by the induced electret state and giant magnetoelectric effect.