Study On The Modification Of M-type Barium Ferrite Materials By The Doping

BaFe₁₂O₁₉ is an important magnetic material,which is widely used in manufacturing inductors,high-density magnetic recording materials,microwave devices and other types of electronic devices.Barium ferrite has excellent performance,with high saturation magnetization,particularly large coercivity,high Curie temperature,and excellent chemical stability.Usually,the performance of barium ferrite can be improved by optimizing the material preparation process and doping of various metal ions.In this paper,the doping effects of transition metals ions of W⁶⁺,Cu-Ti and Cu-Sn on the structure and electromagnetic properties of M-type barium ferrite were studied.The main results can be summarized as follows.?1?The W⁶⁺ doped can replace the site of Fe³⁺ entering into the lattice of barium ferrite.As a result,the lattice constants a and c of barium ferrite would be reduced.W⁶⁺ ion doping can promote the growth of barium ferrite grains,and an appropriate amount of W⁶⁺ ions can improve the densification of the samples.With increasing amount of W⁶⁺ ions,the saturation magnetization decreased,and the coercivity decreased firstly and then increased.With the increase of doping amount of W⁶⁺ ions,the permittivity increases first and then decreases,the magnetic loss tangent increases first and then decreases,and the dielectric constant increases and the dielectric loss decreases.?2?Under the present experimental conditions,the doped Cu²⁺ and Ti⁴⁺ can enter the lattice of barium ferrite,increasing the lattice constants a and c of barium ferrite.Cu-Ti co-doping with equal amount?mole?can promote the growth of barium ferrite grains,and an appropriate amount of Cu-Ti ions can enhance the density of the samples.Cu-Ti co-doping with equal amount has little effect on the saturation magnetization of barium ferrite,resulting in almost no change in the saturation magnetization,but it can reduce the coercivity of ferrites in a large range.The permeability and magnetic loss tangent are almost unchanged after doping with equal amount of Cu-Ti ions.With increasing doping amount of Cu-Ti ions,the dielectric constant increases first and then decreases,and the change in dielectric loss is very weak.?3?Under the present experimental conditions,the doped Cu²⁺ and Sn⁴⁺ can enter the lattice of barium ferrite and increase the lattice constants a and c of barium ferrite.Cu-Sn co-doping with equal amount?mole?can promote the growth of barium ferrite grains,and an appropriate amount of Cu-Sn ions can enhance the density of the samples.Cu-Sn co-doping with equal amount?mole?has little effect on the saturation magnetization of the obtained barium ferrite,resulting in almost no change in the saturation magnetization,but it can reduce the coercivity in a large range.With increasing doping amount of Cu-Sn ions,the permeability increases,the magnetic loss tangent increases first and then decreases,the dielectric constant increases first and then decreases,and the dielectric loss almost keeps unchanged under low frequency,but under high frequency increased first and then reduced.