Carnegie Mellon University

Sara A. Majetich

Professor of Physics
Professor of Electrical & Computer Engineering (Courtesy)
and Professor of Materials Science & Engineering (Courtesy)

Condensed Matter Experiment
Wean Hall 6404

lab website 

Prof. Sara Majetich

Education & Professional Experience

PhD: University of Georgia (1987)
M.A.: Columbia University (1980)

Professional Societies:
Fellow, Institute for Electrical and Electronic Engineers
Fellow, American Physical Society

Honors and Awards:
Carnegie Science Award (2010)
NSF National Young Investigator Awrd (1992)

Curriculum ViTAE

Professor of Physics, Carnegie Mellon University, 1998–
Professor of Materials Science & Engineering (Courtesy), 2013–
Professor of Electrical & Computer Engineering (Courtesy), 2011–
Associate Professor, Carnegie Mellon University, 1995–1998
Assistant Professor, Carnegie Mellon University, 1990–95
Post-doctoral Research: Cornell University, 1987–1990

Research Interests

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.

Recent Publications

Ahmed M. Abdelgawad, Nikhil Nambiar, Muknd Bapna, Hao Chen, and Sara A. Majetich, Magnetic Vortices in Permalloy Nanocaps Induced by CurvatureAIP Advances 8, 056321 (2018)

Bradley Parks, Mukund Bapna, Julianne Igbokwe, Hamid Almasi, Weigang Wang, and Sara A. Majetich, Superparamagnetic perendicular magnetic tunnel junctions for true random number generatorsAIP Advances 8, 055903 (2018)

Mukund Bapna and Sara A. Majetich, Current Control of Time-Averaged Magnetization in Superparamagnetic Tunnel JunctionsApplied Physics Letters 11, 243107 (2017)

C. Moya, A. M. Abdelgawad, N. Nambiar, and S. A. Majetich, Magnetic Properties of Cube-Shaped Fe3O4 Nanoparticles in dilute, 2D, and 3D assemblies, J. Phys. D: Appl. Phys. 50, 325003 (2017)

Zlatko Nedelkoski, Demie Kepaptsoglou, Leonardo Lari, Tianlong Wen, Ryan A. Booth, Samuel D. Oberdick, Daniel Gilks, Quentin M. Ramasse, Richard F. L. Evans, Sara A. Majetich and Vlado K. Lazarov, Origin of reduced magnetization and domain formation in small magnetite nanoparticles, Scientific Reports  7, 45997 (2017)

S. K. Piotrowski et al., Size and voltage dependence of effective anisotropy in sub-100-nm perpendicular magnetic tunnel junctions, Phys. Rev. B 94, 014404 (2016)

A. Hevroni, M. Bapna, S. Piotrowski, S. A. Majetich, G. Markovich, Tracking the Verwey transition in single magnetite nanocrystals by variable-temperature scanning tunneling microscopy, J. Phys. Chem. Lett. 7, 1661 (2016)

L. Tryputen et al., Patterning of sub-50 nm perpendicular CoFeB/MgO-based magnetic tunnel junctions, Nanotechnology 27, 185302 (2016)

A. M. Abdelgawad, S. D. Oberdick, S. A. Majetich, Formation of FePt nanodots by wetting of nanohole substrates, AIP Adv., 6, 056114 (2016)

M. Bapna, S. K. Piotrowski, S. D. Oberdick, M. Li, C.-L. Chien, S. A. Majetich,  Magnetostatic effects on switching in small magnetic tunnel junctions, Appl. Phys. Lett. 108, 022406 (2016)

More Publications:
ORCID  Researcher ID