Glass-Ceramic Synthesis of Cr-Substituted Strontium Hexaferrite Nanoparticles with Enhanced Coercivity
Lev A. Trusov, Anastasia E. Sleptsova, Jingtong Duan, Evgeny A. Gorbachev, Ekaterina S. Kozlyakova, Evgeny O. Anokhin, Artem A. Eliseev, Maxim A. Karpov, Alexander V. Vasiliev, Oleg Brylev, Pavel E. Kazin
Abstract
Magnetically hard ferrites attract considerable interest due to their ability to maintain a high coercivity of nanosized particles and therefore show promising applications as nanomagnets ranging from magnetic recording to biomedicine. Herein, we report an approach to prepare nonsintered single-domain nanoparticles of chromium-substituted hexaferrite via crystallization of glass in the system SrO–Fe2O3–Cr2O3–B2O3. We have observed a formation of plate-like hexaferrite nanoparticles with diameters changing from 20 to 190 nm depending on the annealing temperature. We demonstrated that chromium substitution led to a significant improvement of the coercivity, which varied from 334 to 732 kA m−1 for the smallest and the largest particles, respectively. The results provide a new strategy for producing high-coercivity ferrite nanomagnets.