The surface electronic structure of Ag(100) and A(111) studied with multichannel detection angle resolved photoemission

A new discrete-anode multichannel detector has been installed on a hemispherical electron energy analyser for use in angle-resolved photoemission measurements. Use of the increased sensitivity is illustrated in studies of Ag(001) and Ag(111)surface states. For Ag(001), photoemission from near the point of the surface Brillouin zone evidences two surface states close to the d-band maximum. One, lying at 3.72 eV binding energy(BE), has previously been assigned to a theoretically predicted 2 Tamm state. The second state, which lies at 3.87 eV BE, has previously been ascribed to a surface resonance. It has odd parity with respect to the (100) mirror plane [GH]XWK) and is assigned in this work to a hybridized Shockley state lying in a spin-orbit gap. Hence, the surface electronic structure near the d-band maximum at is found to parallel that previously determined for Cu(001). For Ag(111), use of the multidetector has allowed the L-gap [GH][combining macron] to be measured for the first time.