"Ultrafast and Very Small: Discover Nanoscale Magnetism With Picosecond Time Resolution Using X-Rays"
by Hendrik Ohldag, 2017 Distinguished Lecturer/SLAC
February 24, 2017 | 10:00am-11:00am PST
TANMS Conference Room | WebEx http://tanms.webex.com (Meeting Password: TANMS)
Today’s magnetic device technology is based on complex magnetic alloys or multilayers that are patterned at the nanoscale and operate at gigahertz frequencies. To better understand the behavior of such devices one needs an experimental approach that is capable of detecting magnetization with nanometer and picosecond sensitivity. In addition, since devices contain different magnetic elements, a technique is needed that provides element-specific information about not only ferromagnetic but antiferromagnetic materials as well. Synchrotron based X-ray microscopy provides exactly these capabilities because a synchrotron produces tunable and fully polarized X-rays with energies between several tens of electron volts up to tens of kiloelectron volts. The interaction of tunable X-rays with matter is element-specific, allowing us to separately address different elements in a device. The polarization dependence or dichroism of the X-ray interaction provides a path to measure a ferromagnetic moment and its orientation or determine the orientation of the spin axis in an antiferromagnet. The wavelength of X-rays is on the order of nanometers, which enables microscopy with nanometer spatial resolution. And finally, a synchrotron is a pulsed X-ray source, with a pulse length of tens of picoseconds, which enables us to study magnetization dynamics with a time resolution given by the X-ray pulse length in a pump-probe fashion. The goal of this talk is to present an introduction to the field and explain the capabilities of synchrotron based X-ray microscopy, which is becoming a tool available at every synchrotron, to a diverse audience. The general introduction will be followed by a set of examples, depending on the audience, that may include properties of magnetic materials in rocks and meteorites, magnetic inclusions in magnetic oxides, interfacial magnetism in magnetic multilayers, and dynamics of nanostructured devices due to field and current pulses and microwave excitations.
Hendrik Ohldag received the Ph.D. in experimental physics from the Universität Düsseldorf, Germany, in 2002. He joined the Stanford Synchrotron Radiation Light Source (SSRL) in 1999 as a research assistant as part of his Ph.D. research. After a postdoctoral fellowship at SSRL he became a permanent member of the research staff in 2005. Between 1999 and 2002 he was a visiting researcher at the Advanced Light Source (ALS) at Berkeley National Laboratory. Since 2014 he is a visiting researcher at New York University.
Dr. Ohldag was awarded the David. A Shirley Award at the ALS in 2006 for “outstanding contribution in using photoemission electron microscopy for the study of magnetic materials.” He is a member of the IEEE Magnetics Society and the chair of the Magnetic Interfaces and Nanoscale Device Division of the American Vacuum Society. He has authored or co-authored over 50 peer-reviewed papers and book chapters which have been cited over 2500 times. He has participated in the organization of 25 international conferences and workshops. His research focuses on the use of X-ray microscopy to study the dynamic and static properties of complex magnetic materials.
David Blancha, STEM Manager of Graduate Student Services at UCLA Career Center provides a three part seminar series to help TANMS graduate students prepare for their career search.
Congratulations to TANMS faculty Professors Yuanxun Ethan Wang, Greg Carman, and Chris Lynch for receiving the $2M NSF Emerging Frontiers in Research and Innovations (EFRI) grant for their project titled "EFRI NewLAW: Non-Reciprocal, Parametric Amplification of Acoustic Waves for Future Generation of RF Front-Ends".
NSF Award Announcement: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1641128&HistoricalAwards=false
Press Release by Congressman Ted Lieu: https://lieu.house.gov/media-center/press-releases/congressman-lieu-announces-national-science-foundation-grant-ucla
IAB Meeting: May 16, 2016 @ Luxe Sunset Hotel
NSF Site Visit: May 17-18, 2016 @ Luxe Sunset Hotel (http://www.luxesunset.com)
TANMS faculty, Professor Sayeef Salahuddin, has been named by President Obama as one of 105 recipients of the Presidential Early Career Awards for Scientists and Engineers, the highest honor bestowed by the United States Government on science and engineering professionals in the early stages of their independent research careers.
For the full White House press release, go to https://www.whitehouse.gov/the-press-office/2016/02/18/president-obama-honors-extraordinary-early-career-scientists .
Dr. Salahuddin is an associate professor with UC Berkeley Electrical Engineering and Computer Sciences and a member of TANMS 2-D Thrust. Please join TANMS in congratulating Dr. Salahuddin in this outstanding recognition.
Happy New Year! It is with pleasure that we start off the new year with the introduction of the new TANMS Education Director, Dr. Maria del Pilar O'Cadiz. Dr. O’Cadiz is a native Southern Californian, born to immigrant Mexican parents. She completed her undergraduate studies at Oberlin College in 1986, and two master’s degrees at UCLA (M.Ed. in Curriculum, Administration, and Teaching and M.A. in Latin American Studies). She studied abroad as an undergraduate student at the University of Cordoba, Spain and completed a year of graduate study at the University of São Paulo, Brazil through the UC Education Abroad Program. She earned her Ph.D. in Social Sciences and Comparative Education at UCLA in 1996, receiving the Comparative and International Education Society’s Gail Kelly Outstanding Dissertation Award. Her dissertation work was published in a book, Education and Democracy: Paulo Freire, Social Movements and Educational Reform in São Paulo (1998) co-authored with Pia Lindquist Wong and her doctoral advisor, UCLA distinguished professor, Carlos Alberto Torres.
While completing her doctoral studies at UCLA, Pilar began her engagement in the Out-of-School Time (OST) field as the educational program director, and later executive director, of the Boyle Heights Elementary Institute, a community based organization that provided afterschool and mentoring programs for Latino youth east of downtown Los Angeles, in partnership with UCLA, community leaders and local businesses. It was during this time (1992-1996) that she recognized the potential of OST settings for leveraging community resources in the creation of innovative learning opportunities for diverse youth to develop the academic proficiencies and social skills needed to achieve their higher education and career goals, and facilitate their meaningful civic engagement.
Consequently, Pilar worked for eight years as executive director of the Collaborative After School Project out of UC Irvine and later Cal Poly Pomona, in partnership with the Los Angeles County Office of Education, providing technical assistance and professional development opportunities to youth serving programs. Additionally she has provided evaluation and research services as a consultant for various clients, including LAUSDs Beyond the Bell Branch and the League of California Afterschool Providers. She is currently an active member of the Learning in Afterschool and Summer Project Work Group and an Editorial Board member of the Journal of Expanded Learning Opportunities.
As a Project Scientist at UC Irvine School of Education (2006 to 2015), working with Professor and Founding Dean, Deborah Lowe Vandell, Dr. O’Cadiz has been involved in several evaluative studies of OST programs, including the assessment of student outcomes and program quality in publically funded afterschool and summer learning programs for the California Department of Education, and a recently completed study of a three-year statewide initiative aimed at expanding access to quality STEM learning opportunities, and building student STEM interest, engagement and career aspirations.
Dr. O’Cadiz has also worked teaching and advising undergraduate and graduate students as co-coordinator of the Internship Teaching Program at Pacific Oaks College in Pasadena, and adjunct faculty at Antioch University, Cal State Fullerton, Cal Poly Pomona and UC Irvine. In the past six years she has served on the dissertation committees of doctoral students at Cal State Long Beach, Cal State Fullerton, UC Irvine, USC, Claremont Graduate University, and Chapman University.
Her professional experiences and interactions with talented students and dedicated educators and community leaders over the past two decades will continue to inform and motivate Pilar’s commitment to engaging diverse youth and young adults in 21st century career pathways through innovative expanded learning opportunities in her new role as TANMS Education Director.
Please join me in welcoming Dr. O'Cadiz to the TANMS family. She can be reached at firstname.lastname@example.org or (310) 825-0401. Her office is located in TANMS headquarters at UCLA in Boelter Hall, Room 7702D.
A big thank you to Dr. George Youssef for all of his contributions to TANMS as the former Education Director and for assisting us to ensure a smooth transition process.
The first issue of the official TANMS Newsletter "Multiferroic Focus" is now available for download at https://goo.gl/m4b66h .
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