Analysis of surface- and bulk-plasmon contributions to x-ray photoemission spectra

The plasmon structure accompanying core-level x-ray photoemission in Na, Mg, and Al is reported and analyzed using a model of random spatial emission of extrinsic plasmons. The Mg and Al spectra are well fit by this model without intrinsic plasmon production. The Na data are not explained by purely extrinsic plasmon emission. © 1975 The American Physical Society.