Skip to main content

Sara Majetich

Carnegie Mellon University
Physics
Education
Ph.D., University of Georgia
Profile

Sara Majetich received her B.A. in chemistry from Princeton University, her M.S. in Physical Chemistry from Columbia University, and her Ph.D. in Solid State Physics from the University of Georgia. Following that, she did postdoctoral work at Cornell University before joining the Physics Department at Carnegie Mellon University in 1990, where she now is a full professor. She received several awards including the Ashkin Award for excellence in teaching, the Carnegie Mellon University Undergraduate Advising Award, and a National Young Investigator Award from the National Science Foundation. She has three patents and over 100 publications.
 

Research

My research focuses on magnetic nanoparticles that have very uniform sizes, and we study their fundamental behavior, as well as possible applications in data storage media, permanent magnets, and biomedicine. One of the consequences of this monodispersity is that the particles can then self-assemble into arrays (shown below), just as atoms come together to form a crystal. We are investigating the collective behavior of the nanoparticle arrays that are analogous to those in crystals. Isolated iron atoms do not interact with each other and are paramagnetic, but in an iron crystal the interactions lead to ferromagnetism. Superparamagnetic-to-ferromagnetic and insulator-to-metal phase transitions are expected as the nanoparticles are brought closer together. We have also developed a method to replace the surfactant coating the particles with an inorganic matrix, and are exploring methods that exploit this approach to prepare functional nanocomposites.

Students

Title Position Email
Ahmed Abdelgawad Graduate Student abdel@cmu.edu
Mukund Bapna Graduate Student mbapna@cmu.edu
Farreltin Fan Undergraduate Student
Michael Matty Undergraduate Student
Sam Oberdick Graduate Student samoberdick@gmail.com
Brad Parks Graduate Student bparks@andrew.cmu.edu
Stephan Piotrowski Graduate Student stephan.piotrowski@gmail.com
Alicia Wu Undergraduate Student
Most Cited Publications

"TCE dechlorination rates, pathways, and efficiency of nanoscale iron particles with different properties." Yueqiang Liu, Sara A Majetich, Robert D Tilton, David S Sholl, Gregory V Lowry. Environmental science & technology.
"Synthesis and utilization of monodisperse superparamagnetic colloidal particles for magnetically controllable photonic crystals." Xiangling Xu, Gary Friedman, Keith D Humfeld, Sara A Majetich, Sanford A Asher. Chemistry of Materials.
"Superparamagnetism in carbon-coated Co particles produced by the Kratschmer carbon arc process." ME McHenry, SA Majetich, JO Artman, M DeGraef, SW Staley. Physical Review B.
"The 2014 magnetism roadmap." Robert L Stamps, Stephan Breitkreutz, Johan Åkerman, Andrii V Chumak, YoshiChika Otani, Gerrit EW Bauer, Jan-Ulrich Thiele, Martin Bowen, Sara A Majetich, Mathias Kläui, Ioan Lucian Prejbeanu, Bernard Dieny, Nora M Dempsey, Burkard Hillebrands. Journal of Physics D: Applied Physics.
"Preparation and characterization of monodisperse Fe nanoparticles." Dorothy Farrell, Sara A Majetich, Jess P Wilcoxon. The Journal of Physical Chemistry B.

Recent Publications

"Magnetic stray fields in nanoscale magnetic tunnel junctions." Sarah Jenkins, Andrea Meo, Luke E Elliott, Stephan K Piotrowski, Mukund Bapna, Roy W Chantrell, Sara A Majetich, Richard FL Evans. Journal of Physics D: Applied Physics.
"Electric field switchable magnetic devices." Jian-Ping Wang, Delin Zhang, Sara A Majetich, Mukund Bapna. US.
"The role of faceting and elongation on the magnetic anisotropy of magnetite Fe3O4 nanocrystals." Roberto Moreno, Samuel Poyser, Daniel Meilak, Andrea Meo, Sarah Jenkins, Vlado K Lazarov, Gonzalo Vallejo-Fernandez, Sara Majetich, Richard FL Evans. arXiv preprint arXiv:1909.02470.
"Effect of Mo capping in sub-100 nm CoFeB-MgO tunnel junctions with perpendicular magnetic anisotropy." Mukund Bapna, Brad Parks, Samuel Oberdick, Hamid Almasi, Congli Sun, Paul Voyles, Weigang Wang, Sara A Majetich. Journal of Magnetism and Magnetic Materials.
"Correlated spin canting in ordered core-shell nanoparticle assemblies." Yumi Ijiri, KL Krycka, Ian Hunt-Isaak, Hillary Pan, J Hsieh, Julie A Borchers, James Jennings Rhyne, Samuel D Oberdick, A Abdelgawad, SA Majetich. Physical Review B.