Randall H. Victora

Randall H. Victora

Dr. Victora is a Professor of Electrical and Computer Engineering at the University of Minnesota. He is also Director of the Center for Micromagnetics and Information Technologies (MINT), an industrially funded center for research in data storage. Dr. Victora earned B.S. degrees in Physics and Math from the Massachusetts Institute of Technology in 1980. After receiving his Ph.D. from U.C. Berkeley in 1985, he held research positions at Kodak Research Laboratories until joining academia in 1998. He has several technical contributions used widely within commercial hard disk drives, including Exchange Coupled Composite Media [1-3] that enabled a large increase in areal density. Other contributions include a widely used scaling law [4] that relates magnetic switching fields to measurement times and calculations for magnetic anisotropy [5,6]. Much of his theoretical work on magnetic damping in thin films has been prominently published [7-9]. Most recently, he has developed a spin scattering theory to accurately describe spin torque and magnetoresistance when the ferromagnetic layers are not collinear [9,10] or defective [11,12]. He is one of only two researchers to have twice received the Technical Achievement Award of the Information Storage Industry Consortium (INSIC). He received the 2014 Achievement Award of the IEEE Magnetics Society.  He is a Fellow of the IEEE and the American Physical Society.

1. R.H. Victora and X. Shen, “Composite media for perpendicular magnetic recording,” IEEE Trans. Magn. 41, 537 (2005).
2. J.P. Wang, W.K. Shen, J.M. Bai, R.H. Victora, J.H. Judy, and W.L. Song, “Composite media (dynamic tilted media) for magnetic recording, Appl. Phys. Lett. 86, 142504 (2005).
3. R.H. Victora and X. Shen, “Exchange coupled composite media for perpendicular magnetic recording”, IEEE Trans. Magn. 41, 2828 (2005).
4. R. H. Victora, “Predicted time dependence of the switching field for magnetic materials,” Phys. Rev. Lett. 63, 457 (1989).
5. R.H. Victora and J.M. MacLaren, “Theory of magnetic interface anisotropy”, Phys. Rev. B47, 11583 (1993)
6. J.M. MacLaren and R.H. Victora, “Theoretical predictions for interface anisotropy in the presence of interdiffusion,” J. Appl. Phys. 76, 6069 (1994).
7. A. Yu Dobin and R.H. Victora, “Intrinsic non-linear ferromagnetic relaxation in thin metallic films “, Phys. Rev. Lett. 90, 167 (2003).

A. Yu Dobin and R.H. Victora, “Surface roughness induced extrinsic damping in thin magnetic films,” Phys. Rev. Lett. 92, 257204 (2004).

9. T.Qu and R.H. Victora, “Dependence of Kambersky damping on Fermi level and spin orientation”, J. Appl. Phys. 115, 17C506 (2014)
10. S. Hernandez, and R. H. Victora, “Calculation of spin transfer torque in partially polarized spin valves including multiple reflections,” Appl. Phys. Lett. 97, 062506 (2010).
11. T. Qu and R. H. Victora, “Angular dependence of current perpendicular to plane giant magnetoresistance in multilayer nanowire,” J. Appl. Phys. 111, 07C516(2012).
12. X. Chen and R. H. Victora, “Effect of pin holes in magnetic tunnel junctions,” Appl. Phys. Lett. 91, 212104 (2007).

13. M. M. Maqableh, X. Huang, S.-Y. Sung, K. S. M. Reddy, G. Norby, R. H. Victora, and B. J. H. Stadler, Nano Let. 12, 4102 (2012).