Crystalline electric field splitting

Most commonly occurring operator equivalents required in crystalline electric field splitting calculations (/ = ... 

The crystal electric field. If the exchange is isotropic, and only if the exchange is isotropic, the crystalline electric field splitting determines the magnetic axis. If the values obtained for the crystal electric field are very different from the expectations based on the point-charge model, then application of the CEF theory is doubtful. 

The excess contribution is due to the distribution of the valence electrons over the energy levels, and includes the splitting of the ground term by the crystalline electric field (Stark effect) and is called the Schottky heat capacity or Schottky anomaly. It can be calculated from... 

An array of charges in a crystal produces an electric field at any one ion, the so-called crystalline electric field. The presence of this field causes a Stark splitting of the free ion energy levels which results in a substantial modification of magnetic, electrical and thermal properties of the material. The theory of the crystal field and its interpretation in terms of group theory are originally due to Bethe (16). 

The temperature dependence of the quadrupole splitting in thulium metal between 59 and 156 K has given data concerning the crystalline electric field... 

Fig. 49. Schematic representation of the splitting of the I4 Hand s rule ground state of Np in a tetragonal (elongated) crystalline electric field (CEF). Exchange splitting of the F begins at Tn and increases with lowering the temperature. The major wave function components of the CEF states are indicated. [Taken from Kalvius el al. (1985).]...

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