Structure, dielectric and ferroelectric properties of Ba$_2$NdFeNb$_4$O$_{15}$ multiferroic thin films

The phase composition, nanostructure, and properties of Ba$_2$NdFeNb$_4$O$_{15}$ multiferroic thin films are studied by X-ray diffraction, dielectric spectroscopy, methods for analyzing ferroelectric properties, and scanning probe microscopy. Films were grown on the single-crystal Pt/MgO(001) substrate by a one-stage RF cathode sputtering technique in an oxygen atmosphere. It has been established that the Ba$_2$NdFeNb$_4$O$_{15}$ films are single-phase, impurity-free, and c-oriented, which made it possible to study their dielectric properties along the polar direction. tensile deformation of the unit cell (1.35% along the polar axis) has found in the films, which led to the realization of the ferroelectric phase in the BNFNO film at room temperature. The revealed dependencies and the prospects for using this material in the nanosized thin films form are discussed.