Crystal-field splittings under pressure

Fig. 4. Crystal-field split levels of the multiplet of LaCl3 Pr3+ under pressure, drawn with respect to the center of gravity fixed to zero (dashed line).

As a last remark, it should be mentioned that also a few evaluations of the crystal-field parameters of Pr3"1" in LaCH in the scope of the angular overlap model have been made. Urland et al. (1985) andUrland (1989) used the angular overlap model to calculate the crystal-field splittings of LaCHiPr3"1" under pressure. In addition, Gregorian et al. (1989) derived the parameters of both models and found that both approaches were capable to successfully describe the high-pressure results. 

The pressure dependence of the low-temperature susceptibility of the Pr and Tm pnictides is rather queer. Based on the point-charge model the crystal-field splitting is expected to increase under pressure and therefore the magnetic susceptibility xcf should decrease but th contrary is observed (Guertin et al., 1975). For TmSb the observed value for 5 In =-1-3 x 10 kbar is nearly... 

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