Investigation of resonant photoemission from GdCu2 and Gd5Si4

Resonant photoemission from GdCu2 and Gd5Si4 has been investigated in the photon energy range of the Gd 4d→4f threshold. The emission from the valence Cu 3d and core Cu 3p and Si 2p levels has been studied to check the presence of the multiple atom resonance effect. The anti-resonance on the Cu 3d level has been observed, similar to the one observed earlier for GdCu. The core Cu 3p and Si 2p levels show a different behaviour with a slightly pronounced maximum. One of the possible explanations is based on the resonant light scattering. For the valence Cu 3d level the anti-resonance may be related to the direct interaction between the valence states of Gd and Cu. The resonance behaviour of Gd 5p and 5s multiplets is analysed. The photon dependent lifetime of the photoemission peaks and resonant enhancement of the minority spin peaks are proposed as an explanation of the observed behaviour.