Аннотация:Scanning electron microscopy, X-ray diffraction, Raman and Mössbauer spectroscopies, field and temperature dependences of magnetic saturation and magnetocaloric effect in alternating magnetic fields are used to study submicron yttrium ferrite particles prepared by reverse coprecipitation from nitrate solutions at various pH values and subsequent heat treatment. The size, phase purity, and structural state of prepared particles determine the magnitude of the magnetocaloric effect exhibited by the particles in the external alternating magnetic field (370 kHz, 1.77 kA/m).