1. PEEM2 REVEALS SPIN ALIGNMENT IN MAGNETIC LAYERS
by Art Robinson
(Contacts: FNolting@lbl.gov, A_Scholl@lbl.gov)

Researchers from the ALS, IBM, and Arizona State University have taken a major step toward the solution of a long-standing problem in magnetic multilayers: identifying the mechanism of directional coupling between spins in an antiferromagnet and those in an adjacent ferromagnet. Known as exchange bias, this coupling plays a key role in magnetic devices based on the giant magnetoresistance (GMR) effect. Using the photoemission electron microscope at the ALS (PEEM2), the group obtained x-ray magnetic dichroism images that revealed the magnetic structure on both sides of the interface between a thin layer of ferromagnetic cobalt grown on antiferromagnetic lanthanum iron oxide (LaFeO3), as well as local remanent hysteresis loops for individual ferromagnetic domains. The experiments may lead to a definitive understanding of the elusive mechanism of exchange biasing.

Read the full story at http://www-als.lbl.gov/als/science/sci_archive/spinalign.html.

Publications about this research: F. Nolting, A. Scholl, J. Stöhr, J.W. Seo, J. Fompeyrine, H. Siegwart, J.-P. Loquet, S. Anders, J. Lüning, E.E. Fullerton, M.F. Toney, M.R. Scheinfein, and H.A. Padmore, "Direct observation of the alignment of ferromagnetic spins by antiferromagnetic spins," Nature 405, 767 (2000). A. Scholl, J. Stöhr, J. Lüning, J.W. Seo, J. Fompeyrine, H. Siegwart, J.-P. Loquet, F. Nolting, S. Anders, E.E. Fullerton, M.R. Scheinfein, and H.A. Padmore, "Observation of antiferromagnetic domains in epitaxial thin films," Science 287, 1014 (2000).

2. BERKELEY GEARS UP FOR ICESS8 CONFERENCE
(Contacts: icess@lbl.gov or http://www-als.lbl.gov/icess)

In less than two weeks, about 400 scientists from over 34 countries will convene in Berkeley, California, for a five-day conference on experimental and theoretical aspects of laboratory- and synchrotron-radiation-based electronic spectroscopy. The Eighth International Conference on Electronic Spectroscopy and Structure (ICESS8) is sponsored in part by the ALS, with the Univ. of California, Davis, being the primary sponsor. It will be held at the scenic Clark Kerr Campus of the Univ. of California, Berkeley, on August 8-12, 2000. This year's conference will include 53 invited talks, 50 specially selected contributed talks, about 350 poster presentations, and over 60 student participants, as well as an exhibition of vendors and publishers. Updated program and travel information can be found at the ICESS8 Web site (http://www-als.lbl.gov/icess). Late registration is still possible, so don't miss this golden opportunity to hear and share the latest news on research in electronic spectroscopy and related spectromicroscopies.

3. ALS USERS' MEETING 2000: ABSTRACT SUBMISSION DEADLINE AUGUST 15, 2000
(Contact: alsabstract@lbl.gov)

ALS users, staff, students, and postdocs are reminded that the deadline for the submission of abstracts for poster and/or oral presentations at this year's ALS Users' Meeting is Tuesday, August 15. Highlight oral presentations for the Young Researcher session will be selected by the Users' Executive Committee from the abstracts received; other submissions will be presented during the poster session tentatively scheduled for Monday, October 16. Abstracts can be submitted on line at http://www-als.lbl.gov/als/usermtg/abstracts.html.

General information about the meeting, including a list of workshops proposed for this year's program, can be found at http://www-als.lbl.gov/als/usermtg. Registration and accommodation materials will be mailed out later this summer.

4. TWO-BUNCH REFRESHER

Over the next couple of weeks, the ALS will be operating in two-bunch mode. For new readers who are unfamiliar with this mode of operation, the following quick review may provide some background on what two-bunch mode is and why it's useful.

Electrons circle within the ALS storage ring in bunches, in almost any fill pattern accommodated by the ring's 328 electron "buckets." Normal (multibunch) operation involves filling 276 consecutive buckets with electrons, followed by a gap of 52 empty buckets. In two-bunch operation, only two diametrically opposed buckets are filled with electrons. This results in relatively long intervals between beamline x-ray pulses, enabling researchers to more easily separate interactions at the target. Two-bunch operation is typically used for time-of-flight (TOF) experiments, in which one detector records an event (e.g., the ionization of an atom) and a second detector some distance away records the arrival times of particles (e.g., electrons) generated by that event, yielding a complete energy spectrum of ejected particles. Using this approach considerably reduces background noise levels compared to using electrostatic or magnetic spectrometers. Also, an entire electron spectrum can be collected simultaneously. ALS experiments that have taken advantage of two-bunch operation in the past include chemical dynamics experiments and studies of atomic and molecular structure and dynamics.

5. UEC CORNER: NOTES FROM THE USERS' EXECUTIVE COMMITTEE
by Nora Berrah
(Contact: berrah@wmich.edu)

The members of the UEC are busy preparing for the next Users' Meeting. By now you should have received the first announcement of the meeting, which will be held on October 16-18, 2000. Please check the conference Web site (http://www-als.lbl.gov/als/usermtg) for additional information. We will keep updating the Web site until we finalize the program.

About one-half of the new mezzanine area in the ALS building will be finished and ready for use by the end of this calendar year. The remaining portion will become available by June 2001. The group that will determine the allocation process has user, UEC, and ALS representatives: Carolyn Larabell (Berkeley Lab), Wayne Stolte (Univ. of Nevada, Las Vegas/ALS), Bob Schoenlein (Berkeley Lab), Harald Ade (North Carolina State Univ.), Gary Krebs (ALS), Tomas Baer (Univ. of North Carolina), and Jim Krupnick (ALS).

I would like to remind users requesting space to give the space allocation committee supporting information that will justify your request. Specific information, such as the size of your program, number of endstations, number of permanent and transient staff/users, as well as why proximity to the ALS is important, will help the committee tremendously.

6. WHO'S IN TOWN

The ALS will be operating in two-bunch mode from July 25 - August 6. Following are some of the experimenters who will be collecting data during this time.

Beamline 1.4.3
Phil Huie (Stanford Univ. Medical Center)

Beamline 7.3.3
Alain Manceau (Univ. Joseph Fourier, France)

Beamline 8.0.1
Dennis Lindle (Univ. of Nevada, Las Vegas)

Beamline 9.3.1
Gerardo Gerson de Souza and Antonio Carlos Fontes dos Santos (Univ. Federal do Rio de Janeiro, Brazil)
Marcelo Sant'anna (Univ. Federal Fluminense, Brazil)
Fred Schlachter and colleagues (Berkeley Lab)

Beamline 10.0.1
Nora Berrah and colleagues (Western Michigan Univ.)

7. OPERATIONS UPDATE
(Contact: EJLampo@lbl.gov)

For the user runs of July 11 - 16 and July 19 - 23, the beam availability was 97%. Of the delivered beam, 87% was delivered to completion without interruption. There were no significant outages.

Long-term and weekly operations schedules are available on the Web (http://www-als.lbl.gov/als/accelinfo.html). Requests for special operations use of the "scrubbing" shift should be sent to Gary Krebs (GFKrebs@lbl.gov, x7727) by 1:00 p.m. Friday. The Accelerator Status Hotline at (510) 486-6766 (ext. 6766 from Lab phones) features a recorded message giving up-to-date information on the operational status of the accelerator.