Magnetic anisotropy of Ba ferrite particles at low temperature

The evolution of the magnetic anisotropy of pure and Co/Ti-doped Ba ferrite particles from room to low temperatures is studied analyzing the variation of the anisotropy constants with T. These constants increase with the decrease of temperature in different ways in the two types of particles. In pure particles the magnetocrystalline anisotropy constant K-1 is larger than the conflicting shape anisotropy constant K-S at low as at room temperature, which means uniaxial anisotropy, in all the analysed range of temperatures. In the doped particles, where the substitutions weaken the crystalline anisotropy, at low temperature K-S > K-1, then the particle is not any more uniaxial, but the easy axes have multiple directions.