News

Spurgeon publishes highlight on laser-induced demagnetization in MRS Bulletin

Posted in News on April 15th, 2013 by admin – Comments Off on Spurgeon publishes highlight on laser-induced demagnetization in MRS Bulletin

Steven Spurgeon has published a research highlight in the Materials Research Society Bulletin‘s April 2013 issue discussing laser-induced demagnetization in nickel thin films.

From the article: “The mechanics of laser-induced demagnetization has attracted considerable attention in efforts to develop fast switching optomagnetic logic devices. A femtosecond laser pulse for instance can demagnetize a ferromagnet within a few hundred femtoseconds. Various theories have been proposed to explain how an ultrafast laser pulse can demagnetize a magnetic thin film, ranging from indirect spin-flip scattering to direct laser-induced spin flips. Now, A. Eschenlohr, M. Battiato, and colleagues at Helmholtz Zentrum Berlin and Uppsala University propose that a novel mechanism of superdiffusive electron transport drives the demagnetization. . . .”

The article can be viewed directly here or on the Materials Research Society Bulletin website.

Taheri and colleagues publish in Microscopy and Microanalysis

Posted in News on March 6th, 2013 by admin – Comments Off on Taheri and colleagues publish in Microscopy and Microanalysis

Dr. Taheri and colleagues’ latest paper, titled “A (S)TEM gas cell holder with localized laser heating for in situ experiments” has been published online in the journal Microscopy and Microanalysis.

From the abstract: “The advent of aberration correction for transmission electron microscopy has transformed atomic resolution imaging into a nearly routine technique for structural analysis. Now an emerging frontier in electron microscopy is the development of in situ capabilities to observe reactions at atomic resolution in real time and within realistic environments. Here we present a new in situ gas cell holder that is designed for compatibility with a wide variety of sample type. . .”

A pre-print of the paper can be viewed directly here.

The paper can also be accessed on the Cambridge website: Microscopy and Microanalysis.

DCG students attend 2013 ASU Winter Microscopy School

Posted in News on February 16th, 2013 by admin – Comments Off on DCG students attend 2013 ASU Winter Microscopy School

DCG students James Nathaniel, Wayne Harlow, and Katie Jo Sunday attended Arizona State University’s 2013 Winter School on High Resolution Electron Microscopy in January. James was also awarded a scholarship to cover tuition and help defray travel costs to attend the workshop.

The ASU Winter School is a prestigious workshop held every year by leaders in electron microscopy. From the school’s website, “The aim of the school is to introduce the theory and practice of high resolution electron microscopy to scientists currently using transmission electron microscopes for materials science studies.”

For more information, visit: ASU Winter Microscopy School

Spurgeon awarded APS GMAG Travel Grant

Posted in News on February 16th, 2013 by admin – Comments Off on Spurgeon awarded APS GMAG Travel Grant

Steven Spurgeon has been awarded a travel grant to attend the American Physical Society March 2013 meeting in Baltimore, Maryland. The grant was awarded by the Topical Group on Magnetism and its Applications (GMAG) and covers $250 in travel expenses to attend the conference.

For more details on the APS GMAG, visit: APS GMAG Topical Group

For more details on the APS March Meeting 2013, visit: APS March Meeting 2013

Winkler, Jablonski, Taheri, and colleagues publish in Journal of Applied Physics

Posted in News on September 4th, 2012 by admin – Comments Off on Winkler, Jablonski, Taheri, and colleagues publish in Journal of Applied Physics

Chris Winkler, Michael Jablonski, Dr. Taheri, and colleagues’ latest paper, titled “Accessing intermediate ferroelectric switching regimes with time-resolved transmission electron microscopy” has been published online in the Journal of Applied Physics.

From the abstract: “BiFeO3 (BFO) is one of the most widely studied magneto-electric multiferroics. The magneto-electric coupling in BiFeO3, which allows for the control of the ferroelectric and magnetic domain structures via applied electric fields, can be used to incorporate BiFeO3 into novel spintronics devices and sensors. Before BiFeO3 can be integrated into such devices, however, a better understanding of the dynamics of ferroelectric switching, particularly in the vicinity of extended defects, is needed. We use in situ transmission electron microscopy (TEM) to investigate the response of ferroelectric domains within BiFeO3 thin films to applied electric fields at high temporal and spatial resolution. This technique is well suited to imaging the observed intermediate ferroelectric switching regimes, which occur on a time- and length-scale that are too fine to study via conventional scanning-probe techniques. . .”

The paper can be viewed directly here.

The paper can also be accessed on the AIP website: Journal of Applied Physics.

Spurgeon publishes highlight on Philly Materials Day in MRS Bulletin

Posted in News on September 3rd, 2012 by admin – Comments Off on Spurgeon publishes highlight on Philly Materials Day in MRS Bulletin

Steven Spurgeon has published an article in the Materials Research Society Bulletin‘s October 2012 issue highlighting Philly Materials Day. The article describes the planning and execution of this annual event by faculty at Drexel and the University of Pennsylvania.

From the article: “For a discipline that can be traced back to the construction of the pyramids and the forging of ancient bronze weapons, materials science is still a largely unknown branch of science. Last year, when the US Public Broadcasting Service (PBS) decided to air the NOVA series titled “Making Stuff,” faculty at Drexel University in Philadelphia saw an opportunity to draw attention to the study of solids. . . .”

The article can be viewed directly here or on the Materials Research Society Bulletin website.

More information on Philly Materials Day can be found here.

Also in this issue, Spurgeon describes recent research on room-temperature ferromagnetic spin bags in Sr3YCo4O10+δ oxides. That article is available here or on the Materials Research Society Bulletin website.

Maza Brady receives REU SENSORS poster award

Posted in News on August 21st, 2012 by admin – Comments Off on Maza Brady receives REU SENSORS poster award

Maza REU

SENSORS summer student Maza Brady has received an award for best poster in the National Science Foundation Research Experiences for Undergraduates (REU) summer program.

Maza’s poster, titled “Thermomechanical Processing of Aluminum Alloy to Increase Corrosion Resistance,” was selected among dozens of participants. Maza will be returning to the Santa Clara University to finish her undergraduate degree and plans to enroll in a graduate program in environmental robotics after graduation.

For more information about the REU SENSORS program, please visit: Drexel REU SENSORS

Sloppy, Taheri, and colleagues publish in the Journal of the Electrochemical Society

Posted in News on July 24th, 2012 by admin – Comments Off on Sloppy, Taheri, and colleagues publish in the Journal of the Electrochemical Society

Jennifer Sloppy, Dr. Taheri, and colleagues’ latest paper, titled “Structural investigation of perovskite manganite and ferrite films on yttria-stabilized zirconia substrates” has been published online in theJournal of the Electrochemical Society.

From the abstract: “Here, we report the growth of La0.7Sr0.3MnO3 and La0.7Sr0.3FeO3 films on YSZ (001) substrates using molecular beam epitaxy. Particular emphasis is placed on the structural properties of the film and interface, which are of fundamental importance to all future studies in which model thin film systems are used to investigate interfacial reactions and morphological changes that arise at high temperatures or under polarization. Using a combination of X-ray diffraction and transmission electron microscopy, we find a columnar microstructure with a uniform crystallographic orientation present along the out-of-plane film direction and preferred in-plane orientations relative to the substrate.”

The paper can be viewed directly here.

The paper can also be freely accessed on the ECS website: Journal of the Electrochemical Society.

Spurgeon, Taheri, and colleagues publish in Applied Physics Letters

Posted in News on July 6th, 2012 by admin – Comments Off on Spurgeon, Taheri, and colleagues publish in Applied Physics Letters

Steven Spurgeon, Dr. Taheri, and colleagues’ latest paper, titled “Magnetic properties of Co2C and Co3C nanoparticles and their assemblies” has been published online in Applied Physics Letters.

From the abstract: “Nano-composite material consisting of Co2C and Co3C nanoparticles has recently been shown to exhibit unusually large coercivities and energy products. Experimental studies that can delineate the properties of individual phases have been undertaken and provide information on how the coercivities and the energy product change with the size and composition of the nanoparticles. The studies indicate that while both phases are magnetic, the Co3C has higher magnetization and coercivity compared to Co2C. Through first principles electronic structure studies using a GGA+U functional, we provide insight on the role of C intercalation on enhancing the magnetic anisotropy of the individual phases.”

The paper can be viewed directly here.

The paper can also be accessed on the AIP website at Applied Physics Letters.

Spurgeon, Sloppy, Taheri, and colleagues publish in Journal of Applied Physics

Posted in News on July 5th, 2012 by admin – Comments Off on Spurgeon, Sloppy, Taheri, and colleagues publish in Journal of Applied Physics

Steven Spurgeon and Jennifer Sloppy’s latest paper, titled “A study of the effect of iron island morphology and interface oxidation on the magnetic hysteresis of Fe-MgO (001) thin film composites” has been published online in the Journal of Applied Physics.

From the abstract: “. . .In this study, we report on transmission electron microscopy, electron energy loss spectroscopy, and magnetic characterization of Fe-MgO composite films with various morphologies. We explore relationships between film morphology, intermixing, and the resulting effects on magnetic structure. We find the presence of oxidation at the Fe-MgO interface, with a detrimental impact on the saturation magnetization of the composite. We also observe changes in coercivity and magnetocrystalline anisotropy with film morphology and thickness. These results will inform the design of MgO-based tunnel junctions and improve our understanding of how processing conditions, resulting in morphological and chemical changes such as oxidation, affect magnetization.”

The paper can be viewed directly here.

The paper can also be accessed on the AIP website at Journal of Applied Physics.