Paramagnetic Resonance ofEu2+Dissolved in Yb Metal

The paramagnetic resonance of ${\mathrm{Eu}}^{2+}$ dissolved in Yb metal was measured between 1.6 and 77°K. The $g$ value is $g=1.970\mathrm{}\pm 0.005$, displaying a $g$ shift outside the experimental error. The increase in linewidth with temperature is $\frac{\mathrm{dW}}{\mathrm{dT}}=24\mathrm{}\pm 4$ G/°K independent of the Eu concentration. Assuming that this is caused by the Korringa mechanism, this temperature-dependent linewidth yields a $g$ shift of $\left|\Delta g\right|=0.031\mathrm{}$. From the $g$ shifts, the exchange integral between the Eu spins and the conduction electrons is derived as $J=-0.02\mathrm{}$ eV.