THE ELECTRONIC ALADDIN NEWSLETTER NO. 11

SRC USERS MEETING AND RE-DEDICATION ON MAY 3rd

On May 3 (Saturday), the ceremony marking the renaming of the SRC building in the honor of Ednor M. Rowe will be combined with the Users Meeting. An announcement is being mailed.

PROGRAM

REDEDICATION CEREMONY (10-12 AM):

Welcome:  David L. Huber
Remarks:   John Wiley, Provost
                  Keith Symon, UW-Madison
                  Fred Mills, Argonne National Lab
                  Fred Brown, Univ. of Washington
                  John Weaver, Univ. of Minnesota
                  Giorgio Margaritondo, Lausanne
Unveiling of New Sign:
                  Our Honored Guest, Leni Rowe
Lunch and Informal tour.

SRC USERS GROUP MEETING (1-5 PM)

• User Issues (UAC), Dave Lynch
• Prospects for Infrared, Carol Hirschmugl
• Future of SRC, New Capabilities, Franz Himpsel
• New Undulator Beam Line (PGM), Ruben Reininger
• Spin Polarized Photoemission and MCD, Bill O'Brien
• Scienta Analyzer, Hartmut Hoechst

BANQUET (6 PM)
Announcement of the Aladdin Lamp Award Recipient

SPIN-POLARIZED, ANGLE-RESOLVED PHOTOEMISSION NOW AT SRC

An angle-resolved, spin-polarized photoemission system is now operating the the SRC, using the OMM undulator beam line. This new user instrument, built by Bill O'Brien, combines a mini-Mott spin-polarization detector with a hemispherical electron analyzer. Spin-polarized spectra for Fe films on Pd(100) were obtained in about 3 hours counting time with an angular resolution of +-1 degree and energy resolutions between 0.25 and 0.5 eV. This is only the second beam line in the US to allow a "complete" experiment, i.e., determination of all quantum numbers for electrons in a solid.

MCD EXTENDED TO ALL TRANSITION METALS AND RARE EARTHS

Discussions about future directions at the SRC workshop on magnetic nanostructures last fall lead to a collaborations between SRC staff and users (T.K. Sham, Emil Hallin, Brian Yates, G. Harp, M. Tomaz, Bill O'Brien). Since then, their efforts have extended the spectral range of MCD measurements at SRC such that a continuous source of circular polarization is now available from 10 eV up to 3000 eV. This makes not only the traditional 3d transition metals, but also 4d, 5d transition metals and many rare earths accessible.

Particular results:
Gerry Harp used the new circularly polarized light capabilities of the 6m TGM to investigate the magnetic ordering across the Fe-Pt interface in Fe-Pt multilayers. The Pt 4f-5d transition using circularly polarized light proved to be a very sensitive measurement for the Pt magnetization. Since the Fe, Co and Ni 3p edges are also available on the 6m TGM, this beamline can be used to track both 3d and 5d magnetism, important for many multilayer systems.

A group of researchers (T.K. Sham, Emil Hallin, Brian Yates, G. Harp, M. Tomaz, Bill O'Brien), recently showed the feasibility of performing circular polarization measurements on the Canadian double crystal monochromator (DCM). The energy range of the DCM covers the 2p absorption edges of the 4d elements. Experiments on Fe based Mo, Ru, Rh and Pd multilayers are in progress.

HERMON UPGRADES FOR C1s, O1s, and MCD

A new holographic grating designed to cover the energy range 250-550 eV was received from Zeiss in January, 1997, and installed on (HERMON). A comparison between the measured and calculated flux and resolution curves show that the grating is performing according to specifications. For curves showing HERMON's performance in the 250-1050 eV range contact Mark Bissen.

Another significant enhancement to the beamline was the installation of a motorized, water cooled aperture that allows one to obtain circular polarized light from 250-1000 eV. Contact Bill O'Brien for details.

DIFFRACTION-LIMITED INFRARED MICROSCOPY AT SRC

The IR microspectroscopy beamline achieved diffraction-limited spatial resolution in the wavelength range 2.5-9 microns. This allowed Leo Ocola from CXrL to image the local changes in the resist chemistry caused by exposure and post-exposure bake.

NEW GROWTH CHAMBER FOR MAGNETIC NANOSTRUCTURES

A group of SRC users (M.G. Lagally, W. O'Brien, J.F. MacKay, F.J. Himpsel, B.P. Tonner) is working on a new growth chamber for magnetic nanostructures. It combines sputtering with MBE, which makes it possible to investigate the effects of morphology on magnetism and to compare commercial sputtering processes with lab-based MBE techniques. In use it will be coupled to one of three existing chambers that utilize synchrotron radiation for the study of magnetic films, i.e., magnetic circular dichroism, spin-resolved photoelectron spectroscopy, and x-ray resonant magnetic scattering. An instrumentation proposal was submitted to NSF, received all excellent reviews, and is likely to be funded. This system that should be able to lead SRC into the future by making it possible to prepare sophisticated nanostructures at a synchrotron.

HONORS FOR SRC RESEARCHERS

Prof. Darrel Lynn Judge, long-time SRC user, was elected Fellow of the American Physical Society. The citation stresses his pioneering work on the fundamental properties of atoms and molecules using selective monochromatic photon excitation.

Pupa De Stasio has been awarded the TOYP (The Outstanding Young Person) Award for Science by the Italian Junior Chamber. She received the award for the work on spectromicroscopy of neurons, much of which has been performed at SRC.

Prof. James Taylor (SRC and UW Madison) received the Pharmacia and Upjohn Teaching Award from the Department of Chemistry at UW-Madison for outstanding teaching and his involvement in the creation of the UW-Madison Teaching Academy.

Shashank Misra, a student working with Marshall Onellion at the UW Madison, was awarded the Hilldale Scholarship for Best Senior Thesis.