Solid-phase epitaxy of BiFeO$_{3}$ films with magnetoelectric properties on sapphire

The ferroelectric domain structure has been investigated in bismuth-ferrite rhombohedral phase films prepared on the rhombohedral plane of sapphire by solid-phase epitaxy. The piezoelectric modulus has been estimated to be $d_{33}\sim$ 2 pm/V. In films of the Bi$_{25}$FeO$_{39}$–BiFeO$_{3}$ and Bi$_{2}$Fe$_{4}$O$_{9}$–BiFeO$_{3}$ systems on sapphire, the magnetoelectric-switching effect has been observed in bismuth ferrite crystallites without deposition of exchange-coupled layers. The values of the magnetic moment in bismuth ferrite microcrystallites have been estimated.