OPTICAL SPECTROSCOPY OF DYSPROSIUM ALUMINUM GARNET (DAG)

The absorption spectrum of antiferromagnetic dysprosium aluminium garnet (DAG) (TN=2.50 °K) has been investigated at low temperatures. The groundstate splitting due to all interactions in the antiferromagnetic state is (5.27±0.10) cm-1 extrapolated to 0 °K. The temperature dependence of the lineshift of the absorption lines is measured. Zeeman effect studies give the g-tensor of the groundstate as gz=18.4±0.5, gx=gy=0.5±0.2. The studies also allow the determination of the critical fields as Hc[100]=(5.0±0.1) koe, Hc[111]=(3.9±0.2) koe and Hc[110]=(4.9±0.6) koe. In addition an investigation of a number of satellite lines is performed. Some of them can be interpreted as spin wave sidebands (Stokes and anti-Stokes); others obviously come from dysprosium ions which have impurity ions on regular lattice sites as neighbours. © 1969 Springer-Verlag.