Easy-axis anisotropy

Thermofluctuational behavior of the magnetic moment in a magnetically anisotropic particle acquires new features in comparison with the isotropic case and, accordingly, extends the set of relaxation times. Let us consider a single-domain particle with the easy-axis anisotropy defined by... 

Fig. 9. Relative magnetisation curves for an array of magnetic ions with random easy axis anisotropy at T = 0 K.

Barrier for spin reversal Given a system with a total spin moment of 5 = 5 and easy-axis anisotropy, calculate the energies of the different Ms components of the ground state wave function. 

The A = Pr phase, which does not exist for the B = Ti series has been assigned a spin ice ground state from studies using a variety of probes such as a.c. susceptibility, neutron scattering and heat capacity. Note the easy axis anisotropy and slightly positive Oq which match with the canonical spin ices for the heavy rare earths, A = Dy and Ho. However, some unusual very low temperature spin dynamics surest unique properties for this new spin ice. 

The magnetization M in a ferrimagnetic material is always bound to a certain preferred crystallographic direction, which is the easy axis. Anisotropy energy Fk is required to turn M from the easy axis direction to any other direction. Phenomenologically, this magnetocrystalline anisotropy can be described, to a... 

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