Substitution of Sn in the high-permeability MnZn ferrite for wide temperature applications

To meet the challenge of varied working temperatures of inductance components in new energy vehicle and 5G communication, the high-TC high-permeability MnZn ferrite with excellent temperature stability was developed by the addition of SnO2. In this series of samples, initial permeability mu i maintains large values in a wide temperature range. With increasing the SnO2 content, the temperature of the second permeability peak Tsp decreases and meanwhile Curie temperature TC maintains as high as 160 degrees C. For the best sample with 6000 ppm SnO2, mu i at 25 degrees C is 7244 and exhibits the excellent temperature stability with the low specific temperature coefficient of 0.35 x 10-6 degrees C- 1 between 25 and 130 degrees C. The addition of SnO2 generates Fe2+ and adjusts the magnetocrystalline anisotropy constant K1 = 0 point, which is responsible for the wide-temperature high permeability. The effect of SnO2 addition on magnetization process has also been clarified.