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 N\'eel point was observed at 85^∘{}K. The ferromagnetic-antiferromagnetic transition temperature inferred from the magnetic data was 19.6^∘{}K. The saturation moment, σ_∞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 N\'eel point. The a-axis resistivity curve showed a change in slope at the N\'eel point and was well behaved elsewhere.