Magnetoelastic properties of epitaxial holmium and erbium thin films

Abstract

The magnetoelastic (MEL) stresses of single crystal Ho and Er thin films are measured at low temperatures and in applied magnetic fields up to 12 T by means of a capacitive cantilever technique, to determine the irreducible second-order basal plane MEL stress Bγ,2. For Ho, the data are well fit by the Callen and Callen law, giving Bγ,2=0.29 GPa at 0 K and 12 T, slightly larger than the bulk value, which suggest a negligible effect of the clamping on Bγ,2. For Er, the lack of saturation prevents the determination of the single-ion contribution to Bγ,2 at 0 K. Nevertheless, its sign, which is negative, agrees with the theoretical crystal field prediction.