Magnetization and Electrical Resistivity of Erbium Single Crystals

The magnetic properties of erbium single crystals (hcp) grown by the Bridgman method have been determined in fields up to 18 kilo-oersteds with the field applied parallel to and perpendicular to the $c$ axis at 4.2°K and between 20.4°K and 300°K. The $c$ axis was found to be the direction of easy magnetization. A Néel point was observed at 85°K. The ferromagnetic-antiferromagnetic transition temperature inferred from the magnetic data was 19.6°K. The saturation moment, ${\sigma }_{\infty 0}$, obtained by extrapolation of the $c$-axis data was 8 Bohr magnetons compared to the theoretical 9. Electrical resistivity measurements from 1.3°K to 300°K with the current parallel to the $c$ axis showed a sharp increase in resistivity at 20.4°K, the ferromagnetic-antiferromagnetic transition temperature; a large peak occurred at 53.5°K, and a minimum occurred at the Néel point. The $a$-axis resistivity curve showed a change in slope at the Néel point and was well behaved elsewhere.