OBTAINING MAGNETICALLY SOFT MANGANESE-ZINC FERRITES BY SOL-GEL METHOD Russian patent published in 2024 - IPC B22F9/24 H01F1/11 C04B35/624 

FIELD: chemistry; powder metallurgy.

SUBSTANCE: invention relates to powder metallurgy and chemical engineering and specifically to methods of producing manganese-zinc ferrites. Magnetically soft manganese-zinc ferrites can be used in devices of sensors (memory magnetically operated sealed contacts). Powders of magnetically soft manganese-zinc ferrites are obtained by synthesis from solutions of metal salts by a sol-gel method. Solutions of salts containing Zn²⁺ ions are mixed in the form of Zn(NO₃)₂⋅6H₂O, dissolved in distilled water, or ZnO, previously dissolved in 65 wt.% nitric acid, containing Mn²⁺ ions in the form of Mn(CH₃COO)₂⋅4H₂O and containing Fe³⁺ ions in the form of Fe(NO₃)₃⋅9H₂O. Solutions are stirred with a magnetic mixer at rate of 300–350 rpm until the salts are dissolved, and a citric acid solution is added in amount of 3 mol of acid per 1 mol of the total amount of salts. After stirring, 25 wt.% aqueous ammonia solution is added to the solution to pH=8 and said solution is evaporated in a water bath. Obtained mass is heated in furnace to 200 °C for 5 hours, cooled with furnace to room temperature. Obtained sintered sample is crushed to a powder state, heated in a ceramic crucible in furnace to 500 °C for 2 hours and held at this temperature for 6 hours with subsequent cooling in air to room temperature. Powder in corundum crucible is heated to 1,000 °C for 5 hours, with holding at 1,000 °C for 20 hours with further cooling in air.

EFFECT: obtaining material with high resistance to temperature changes and electromagnetic interference.

1 cl, 3 dwg, 2 tbl, 1 ex