JZ-state

Since HB depends on Jz, states with different Mj values are split by the magnetic field. 

Fig. 17.18 agrees to a first approximation with the prediction of this model. Similarly the temperature dependence of the quadrupole splitting which is produced by thermal excitation within the Jz states split by the exchange... 

Thulium is magnetically ordered in the alloy Fe2Tm, and the internal magnetic field decreases from 7200 kG at 4 K to 1800 kG at 400 K [174]. Detailed analysis of the magnetic and quadrupole interactions gave A e/i g = -2-17(10) and — -1-3 barn. The field at the Tm is produced by an exchange interaction between the 4/-electrons and the iron atoms. This dominates the crystal-field interaction, prevents substantial mixing of the Jz states, and allows a comparatively simple analysis of the detailed data to be made. 

In the method of operator equivalents, the hamiltonian operator of (18.107) is replaced by equivalent angular momentum operators which operate on the L, S, J, Jz states of the ion resulting from the spin-orbit interaction. Thus,... 

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