Disclosed is a method for manufacturing a 
manganese zinc ferrite film through a 
sol-
gel method. The method comprises the steps that 1, 
ferric nitrate and 
zinc nitrate are weighed according to the Mn<0.5>Zn<0.5>Fe<2>O<4> stoichiometric proportion, and the two raw materials are dissolved in deionized water; 2, a manganous 
nitrate solution is added to a solution obtained in the step 1, 
citric acid is added as a complexing agent, and a 
mixed solution is obtained; 3, 
ammonia water is added to the 
mixed solution obtained in the step 2, the pH value of the solution is adjusted to range from six to seven, 
sol is obtained, and then 
polyvinylpyrrolidone is added in the 
sol; 4, a 
silicon substrate is washed through a 
hydrochloric acid and 
hydrofluoric acid mixed 
aqueous solution and is blow-dried through 
nitrogen; 5, the 
manganese zinc ferrite sol obtained in the step 3 is dropped on the 
silicon substrate washed in the step 4, a KW-4A spin coater is used for whirl 
coating by 2,000-3,000 r / min, the sol is evenly distributed on the surface of the 
silicon substrate, then after the silicon substrate is placed in a 
muffle furnace of 250 DEG C to 300 DEG C for heat treatment for 20-30 min, the silicon substrate is heated to 500 DEG C along with the furnace, and the silicon substrate is taken out after heat preservation is kept for 20-30 min. the temperature 
rise rate along with the furnace is 10-20 DEG C / min, and the 
furnace temperature change is within + / -5 DEG C.