Showing papers by "Wolfgang Eberhardt published in 2003"
TL;DR: The collapse of the magnetic exchange splitting in 7 monolayer thick epitaxial Ni/W(110) films following a femtosecond laser pulse was measured using time-resolved photoemission spectroscopy.
Abstract: The collapse of the magnetic exchange splitting in 7 monolayer thick epitaxial Ni/W(110) films following a femtosecond laser pulse was measured using time-resolved photoemission spectroscopy Ultrafast demagnetization during the laser induced hot electron cascade proceeds via spin-flip excitations with a relaxation time constant of 300+/-70 fs At longer times the electronic system cools down and the magnetization is finally reestablished with a time constant of 32+/-02 ps
197 citations
TL;DR: In this paper, the electronic and magnetic properties of Co2Cr0.6Fe0.4Al were investigated using circularly polarized synchrotron radiation and photoemission electron microscopy (PEEM).
Abstract: Heusler compounds are promising candidates for future spintronics device applications. The electronic and magnetic properties of Co2Cr0.6Fe0.4Al, an electron-doped derivative of Co2CrAl, are investigated using circularly polarized synchrotron radiation and photoemission electron microscopy (PEEM). Element specific imaging reveals needle shaped Cr rich phases in a homogeneous bulk of the Heusler compound. The ferromagnetic domain structure is investigated on an element-resolved basis using x-ray magnetic circular dichroism (XMCD) contrast in PEEM. The structure is characterized by micrometre-size domains with a superimposed fine ripple structure; the lateral resolution in these images is about 100 nm. The domains look identical for Co and Fe giving evidence of a ferromagnetic coupling of these elements. No ferromagnetic contrast is observed at the Cr line. Magnetic spectroscopy exploiting XMCD reveals that the lack of magnetic moment, detected in a SQUID magnetometer, is mainly due to the moment of the Cr atom.
63 citations
TL;DR: In this paper, it was shown that the experimentally observed electron lifetimes can be described satisfactorily in terms of two key parameters: the penetration length of the image state into the bulk and the energy phase space available for the quasiparticle decay.
Abstract: The fs dynamics of electrons in image states has been modeled on a variety of noble and transition metal surfaces. It is shown that the experimentally observed lifetimes can be described satisfactorily in terms of two key parameters: the penetration length ${z}_{0}$ of the image state into the bulk and the energy phase space S available for the quasiparticle decay.
12 citations