Magnetic ordering of thin Gd overlayers

1--6-monolayer-thick films of Gd have been studied with use of synchrotron-radiation photoemission. A method is described that utilizes the linear light polarization to obtain information about the overlayer magnetization. The method is complementary to electron-spin-polarization techniques. The thinner Gd overlayers exhibit a local magnetization component along the surface normal that decreases for thicker overlayers. The Gd films exhibit a 5d exchange splitting that changes from approximately 1.1 to 0.6 eV as the overlayer thickness increases.