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Spin-polarized photoemission was employed to investigate the temperature dependence of the exchange splitting of Gd(0001) for both the surface state near the Fermi level EF and the 5d bulk bands. The bulk bands at 1–2 eV below E F show Stoner-like behavior where two peaks with opposite spin polarization shift toward each other as the temperature increases. In contrast, the temperature dependence of the surface state indicates spin-mixing behavior due to fluctuating local moments. These differences are attributed to the degree of itinerancy of the 5d electrons in the two cases.