4 X-ray Dichroisms in Spherical Tensor and Green’s Function Formalism
125
Fig. 4.18 Angular dependence of a quadrupole transition for a 3d 9 ion in O h crystal field (10D q =
1.1 eV) with an exchange field aligned along the z-axis (B = 0.05 eV). a The wave vector (k) is
aligned with [100]. The angular dependence is computed by rotating the polarization vector ()
about [100] with θ = 0 o for [001]. b k is aligned with [001] and is rotated about the [001]
with θ = 0 o for [100]
This is illustrated in Fig. 4.22 where in panel (a) we show the structural dichroism
signal for the same system without an exchange field and in panel (b) the difference
between the case with exchange versus without exchange. The magnetic contribution
is about three orders of magnitude less than the structural contribution for this system.
125
Fig. 4.18 Angular dependence of a quadrupole transition for a 3d 9 ion in O h crystal field (10D q =
1.1 eV) with an exchange field aligned along the z-axis (B = 0.05 eV). a The wave vector (k) is
aligned with [100]. The angular dependence is computed by rotating the polarization vector ()
about [100] with θ = 0 o for [001]. b k is aligned with [001] and is rotated about the [001]
with θ = 0 o for [100]
This is illustrated in Fig. 4.22 where in panel (a) we show the structural dichroism
signal for the same system without an exchange field and in panel (b) the difference
between the case with exchange versus without exchange. The magnetic contribution
is about three orders of magnitude less than the structural contribution for this system.