Sunday, June 22, 2014

Induced Ferromagnetism at BiFeO3/YBa2Cu3O7 Interfaces

Dr. Haraldsen (@JMU Physics and Astronomy) and collaborators from Los Alamos National Laboratory (@LANL) and Nanyang Technological University just published a paper in Scientific Reports (@SciReports) on the induction of ferromagnetism at the interface of BiFeO3 and YBa2Cu3O7.

In this work, Dr. Haraldsen and his collaborators worked to explain the presence of ferromagnetism in a complex oxide heterostructure that should not have that kind of magnetism. Using density functional theory, Drs. Jian-Xin Zhu and Xiao-Dong Wen were able to determine the magnetic energies for various magnetic configurations. Using these energies, Dr. Haraldsen model the configurations and extracted the superexchange couplings between the Fe ions. This analysis showed that the Fe ions at the interface with YBCO produced a ferromagnetic moment. This was then used to explain the magnetic measurements made by Drs. Mi He, C. Panagopoulos, and Elbert E. M. Chia, who used squid magnetometry to investigate the magnetic moment and overall magnetization of various heterostructures.

For further information, please contact J.T. Haraldsen at

Induced Ferromagnetism at BiFeO3/YBa2Cu3OInterfaces

Jian-Xin Zhu, Xiao-Dong Wen, J. T. HaraldsenMi He, C. Panagopoulos Elbert E. M. Chia

Scientific Reports 4, 5368 (2014). 

Friday, June 13, 2014

Undergraduate Research Experience at the Duke University's Free Electron Laser Laboratory

Even Meekins, a junior physics major in the Department of Physics and Astronomy at JMU, took part recently in a 7-day nuclear astrophysics experiment that was successfully performed at the Free Electron Laser Laboratory located on the campus of Duke University in Durham, North Carolina.

Evan is part of  Dr. Adriana Banu's nuclear astrophysics research group here at JMU. Early this year Dr. Banu was funded by the Research Corporation for Science Advancement for her proposed research that aims to contribute to enhancing the current state of fundamental knowledge on a forefront topic in nuclear astrophysics - the nucleosynthesis beyond iron of the rarest stable isotopes in the cosmos, the so-called p-nuclei. More specifically, the research project is focused on constraining the origin of the p-nuclei by measuring key astrophysical photonuclear reaction cross sections with quasi-monochromatic photon beams at Duke University's High Intensity Gamma-ray Source (HIGS) facility, currently the most intense accelerator-driven gamma-ray source in the world.

Evan Meekins and Dr. Adriana Banu during their recent experiment at the Duke University's HIGS facility

Working at HIGS - Evan Meekins in his own words:
"While I love the physics department at JMU, especially the array of materials the physics department has for the students to experiment, the HIGS and TUNL facilities at Duke University are truly awe-inspiring. Being able to experience, albeit only analyzing the data, equipment and electronics that could create high energy photons and evaluate many, if not all, of the possible characteristics of said photons, along with any reactions that they might produce. I also greatly enjoyed the staff working at HIGS; they were very knowledgeable about the physics behind each aspect of the experiment, as well as friendly and interpersonal.  The experiment itself required a good amount of work, in setting up the equipment properly, collecting the data, and analyzing the data, but was all extremely intellectually fulfilling.  I left the HIGS facility feeling greatly more confident in both my ability to perform experimental physics and my understanding of the fundamental physics behind the experiment. I would greatly recommend any physics student to participate in an upper-level experiment, and would cite the HIGS facility at Duke University as a great place to start."

Monday, June 02, 2014

Research presentations at various Academy of Sciences!

On May 15 2014, the JMU Undergraduate Students Harkirat Mann and Brian Lang, doing research with Dr. Scarel, presented  the research on Infrared and thermoelectric power generation in thin atomic layer deposited thermoelectric films” at the 92th Annual Meeting of the Virginia Academy of Science held at the Virginia Commonwealth University in Richmond (VA).  The work was performed in collaboration with J.-P. Niemelä and M. Karppinen of Aalto University in Finland.  The same day, 8 time zones away, at the Russian Academy Of Sciences in Nizhny Novgorod (Russia), Dr. Scarel presented Infrared power generation: basic phenomena and engineering through materials properties”.  In the picture on the right, Dr. Scarel is in Nizhny Novgorod next to the monument to Nikolay Bogolyubov, a famous russian physicist who made important contribution in Statistiacal Mechanics.