Ruihua Cheng, Ph.D.
My research is mainly to study the phenomena of nanomagnetism through the fabrication and characterization of magnetic nanostructure materials with the goal of understanding the new materials phenomena and exploring and potential technological applications in spintronic devices and sensors.
Nanomagnetism refers to reducing magnetic systems down to the nanometer. It has been shown that the finite-size effects can be harnessed and utilized in a wide range of new technology applications.
The fundamental magnetic properties such as spontaneous magnetization, magnetic anisotropy, the magnitude of spin and orbital moments and magnetic interactions are strongly dependent on the geometry confinement of a given system. Magnetic nanodots and nanowires can be fabricated by molecular beam epitaxial growth. The magnetic and electronic properties of these nanostructures can be characterized in situ .
Spin-dependent transport in hybrid structures involves a combination of ferromagnetic (F) and semiconductor or normal metals.
The interplay between the different types of interactions and correlations present in each can produce a host of interesting spin-dependent effects. We study t he spin-dependent transport in confined geometries including quantum dots, quantum wires, magnetic single-electron transistors, hybrid multilayers, and thin ferromagnetic films. Many of which have direct potential for applications .
1. Mei-xian Wang, Fan Xu, Qi Liu, Hong-fang Sun, Ruihua Cheng, Hao He, Eric A. Stach, and Jian Xie, Enhancing the catalytic performance of Pt/C catalysts using steam-etched carbon blacks as a catalyst support Carbon, 49, 256-265 (2011).
2. Ruihua Cheng, B. L. Justus, A. Rosenberg, D.N. McIlroy, Z. Holman, L. Silvers, D. Zhang, and Y. Kranov The Magnetic Domain Configuration in Co/Ni/Co Nanoscale Antidot Arrays J Appl. Phys. 108, 086110 (2010).
3. Ruihua Cheng, J. Carvell and F.Y. Fradin, Room Temperature Electric Transport Properties of Single C60 Studied by STM and Break Junctions J. Appl. Phys. 108, 053720, (2010).
4. J. Carvell, Ruihua Cheng, Study of Electrical Polarization Hysteresis in Ferroelectric Polyvinylidene Fluoride Films Mat. Letts. 64, 1992, (2010).
5. J. Carvell, E. Ayieta, A. Gavrin, Ruihua Cheng, S. Valloppilly, and P. Sokol, Magnetic Properties of Fe Nanoparticles J. Appl. Phys. 107, 103913, (2010).
6. E. Ayieta, J. Carvell, Ya B. Losovyj, and Ruihua Cheng, Angle Resolved Photoemission Study of Surface States on Pt(997) Vicinal Surface Phys. Lett. A 374, 3080, (2010).
7. J. Carvell, E. Ayieta, Merrill Johnson, and Ruihua Cheng, Characterization of Iron Nanoparticles Synthesized by High Pressure Sputtering Mat. Letts. 63, 715, (2009).
8. Ruihua Cheng, S.D. Bader, and F.Y. Fradin, Strong Magnetic Surface Anisotropy of Ultrathin Fe on Curved Pt (111) Phys Rev. B, 77, 024404, (2008).
9. Ruihua Cheng, S.D. Bader, and F.Y. Fradin, Magnetic Properties of Fe on Vicinal Pt (111) J. Appl. Phys, 103, 07B729, (2008).