Carnegie Mellon University

Sara A. Majetich

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

Condensed Matter Experiment
Wean Hall 6404

lab website

Prof. Sara Majetich

Education & Professional Experience

Ph.D.: 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 Award (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

Roberto Moreno et al., The role of faceting and elongation on the magnetic anisotropy of magnetite Fe3O4 nanocrystals, Scientific Reports 10, 2722 (2020)

Bradley Parks et al., Magnetoresistance Dynamics in Superparamagnetic Co-Fe-B Nanodots, Phys. Rev. Appl. 13, 014063 (2020)

Sarah Jenkins et al., Magnetic Stray Fields in Nanoscale Magnetic Tunnel Junctions, J. Phys. D: Appl. Phys. 53, 044001 (2020)

Mukund Bapna et al., Effect of Mo capping in sub-100nm CoFeB-MgO tunnel junctions with perpendicular magnetic anisotropy, JMMM 483, 34 (2019)

Y. Ijiri et al., Correlated spin canting in ordered core-shell Fe3O4/MnxFe3-xO4 nanoparticle assemblies, Phys. Rev. B 99, 094421 (2019)

Kathryn L. Krycka et al., Spin waves across three-dimensional, close-packed nanoparticles, New J. Phys. 20 123020 (2018)

Mukund Bapna et al., Spin Orbit Torque Switching in 20 nm Perpendicular Magnetic Tunnel Junctions, Phys. Rev. Appl. 10, 024013 (2018)

Samuel D. Oberdick et al., Spin canting across core/shell Fe3O4/MnxFe3-xO4 nanoparticles, Scientific Reports 8, 3425 (2018)

Ahmed M. Abdelgawad et al., Magnetic Vortices in Permalloy Nanocaps Induced by CurvatureAIP Advances 8, 056321 (2018)

Bradley Parks et al., 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 JunctionsAppl. Phys. Lett. 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)

More Publications:
ORCID  Researcher ID