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.

Selected Publications

S. K. Piotrowski et al., Size and voltage dependence of effective anisotropy in sub-100-nm perpendicular magnetic tunnel junctionsPhys. 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 microscopyJ. Phys. Chem. Lett. 7, 1661 (2016)

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

A. M. Abdelgawad, S. D. Oberdick, S. A. Majetich, Formation of FePt nanodots by wetting of nanohole substratesAIP 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 junctionsAppl. Phys. Lett. 108, 022406 (2016)

V. K. Sakharov, R. A. Booth, S. A. Majetich, High-frequency permeability of Ni and Co particle assembliesJournal of Applied Physics 115, 17 (2014)

Samuel D. Oberdick, Sara A. Majetich, Electrophoretic Deposition of Iron Oxide Nanoparticles on TemplatesThe Journal of Physical Chemistry C 117, 18709 (2013)

Tianlong Wen, Ryan A. Booth, Sara A. Majetich, Ten-Nanometer Dense Hole Arrays Generated by Nanoparticle LithographyNano Letters 12, 5873 (2012)

Tianlong Wen, Sara A. Majetich, Ultra-Large-Area Self-Assembled Monolayers of NanoparticlesACS Nano 5, 8868 (2011)

S. A. Majetich, T. Wen, R. A. Booth, Functional Magnetic Nanoparticle Assemblies: Formation, Collective Behavior, and Future DirectionsACS Nano 5, 6081 (2011)

Kazuo Yamamoto, Charles R. Hogg, Saeki Yamamuro, Tsukasa Hirayama, Sara A. Majetich, Dipolar ferromagnetic phase transition in Fe3O4 nanoparticle arrays observed by Lorentz microscopy and electron holographyApplied Physics Letters 98, 072509 (2011)

JitKang Lim, Caitlin Lanni, Eric R. Evarts, Frederick Lanni, Robert D. Tilton, Sara A. Majetich, Magnetophoresis of NanoparticlesACS Nano 5, 217 (2011)

K. L. Krycka et al., Core-Shell Magnetic Morphology of Structurally Uniform Magnetite NanoparticlesPhysical Review Letters 104, 207203 (2010)

Eric R. Evarts, Limin Cao, David S. Ricketts, Nicholas D. Rizzo, James A. Bain, Sara A. Majetich, Spin transfer torque switching of magnetic tunnel junctions using a conductive atomic force microscopeApplied Physics Letters 95, 132510 (2009)

Kazuo Yamamoto, Sara A. Majetich, Martha R. McCartney, Madhur Sachan, Saeki Yamamuro, Tsukasa Hirayama, Direct visualization of dipolar ferromagnetic domain structures in Co nanoparticle monolayers by electron holographyApplied Physics Letters 93, 082502 (2008)

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ORCID  Researcher ID