Erbium magnetic structures

The temperature dependence of the magnetic field and quadrupole interaction in erbium metal have been followed between 4-2 and 40 K and analysed [142]. An estimate of —1-9(4) bam was suggested for the excited-state quadra-pole moment. In a more detailed study, the line intensities of the hyperfine spectrum in a single crystal of Er metal have been correlated with the magnetic structure previously determined by neutron diffraction methods [143]. 

Costes, J.P., Clemente-Juan, J.M., Dahan, R etal. (2002) Unprecedented ferromagnetic interaction in homobin-uclear erbium and gadolinium complexes structural and magnetic studies. Angewandte Chemie International... 

The magnetic term in the heat capacity is what would be expected from the ferromagnetic spiral (i.e. the cone) structure of erbium (Kaplan 1961) and has been supported by the discovery of a linear spin-wave dispersion law along the c-axis in neutron scattering experiments (Nicklow et al. 1971). 

Fig. 6.11. Results of Feron et al. (1970) for the u-axis magnetization of erbium. The spiral-transition at Hd is followed by a transition at between two fan structures.

Erbium exhibits a complex magnetic behaviour, with at least four obserrable characteristic temperatures below rN = 85K, the moments order in a sinusoidal c-axis modulated (CAM) structure at rH=54K, there appears a component perpendicular to the c-axis resulting in a helicoidal structure this intermediate phase exhibits a sequence of lock-in transitions of commensurate phases (spin-slip structures) with wave vectors fm = f, 4 observed by iX-ray scattering (Gibbs et al. 1986), the... 

---