MEASUREMENT OF THE ELECTRON-AFFINITY OF LANTHANUM

The electron affinity of lanthanum has been measured using laser photo electron energy spectroscopy. This is the first electron affinity meas urement for lanthanum and one of the first measurements of an electron affinity of a rare-earth series element. The electron affinity of lan thanum was measured to be 0.47 +/- 0.02 eV. At least one bound excited state of La- was also observed in the photoelectron spectra and the b inding energy relative to the ground state of lanthanum was measured a s 0.17 +/- 0.02 eV. The present experimental measurements are compared to a recent calculation.