Spray pyrolysis synthesis, electrical and magnetic properties of HoxBi1-xFeO3 nanocrystals.

Bismuth ferrite nanopowders doped with holmium ions were synthesized by spray pyrolysis. By means of the TEM and SEM methods, it was established that Ho_xBi_1-xFeO₃ particles have dimensions in the range of 50–170 nm and are agglomerated into spherical formations with a size of 1.5–3 μm. A decrease in the lattice parameters and unit cell volume of holmium-doped bismuth ferrite samples was shown, and the EDX data confirm the incorporation of holmium ions into the positions of bismuth ions in the BiFeO₃ lattice. Doping of bismuth ferrite with holmium ions led to a significant increase in the saturation magnetisation and residual magnetisation in comparison with undoped BiFeO₃, while the coercive force decreased. Magnetic characteristics of Ho_xBi_1-xFeO₃ samples demonstrated strong dependence on temperature, and the dielectric permittivity in the frequency range up to 200 kHz remains practically unchanged. Magnetocapacitance values in fields up to 5 × 10⁵ A/m did not exceed a tenth of a percent, which is associated with a high dispersion of nanopowders. The values of M_s and M_r obtained for Ho_xBi_1-xFeO₃ open up prospects for using this material for the development of magnetic field sensors, memory cells, and spintronic devices. [ABSTRACT FROM AUTHOR]