Magnetic Vortex Reveals Key to Spintronic Speed Limit

UPTON, NY — The evolution of digital electronics is a story of miniaturization – each generation of circuitry requires less space and energy to perform the same tasks. But even as high-speed processors move into handheld smart phones, current data storage technology has a functional limit: magnetically stored digital information becomes unstable when too tightly packed. The answer to maintaining the breath-taking pace of our ongoing computer revolution may be the denser, faster, and smarter technology of spintronics.

Spintronic devices use electron spin, a subtle quantum characteristic, to write and read information. But to mobilize this emerging technology, scientists must understand exactly how to manipulate spin as a reliable carrier of computer code. Now, scientists at the Department of Energy’s (DOE) Brookhaven National Laboratory have precisely measured a key parameter of electron interactions called non-adiabatic spin torque that is essential to the future development of spintronic devices... Read more

Unprecedented Subatomic Details of Exotic Ferroelectric Nanomaterials

As scientists learn to manipulate little-understood nanoscale materials, they are laying the foundation for a future of more compact, efficient, and innovative devices. In research to be published online July 8 in the journal Nature Materials, scientists at the U.S. Department of Energy’s Brookhaven National Laboratory, Lawrence Berkeley National Laboratory, and other collaborating institutions describe one such advance — a technique revealing unprecedented details about the atomic structure and behavior of exotic ferroelectric materials, which are uniquely equipped to store digital information. This research could guide the scaling up of these exciting materials and usher in a new generation of advanced electronics.

Brookhaven scientists used a technique called electron holography to capture images of the electric fields created by the materials’ atomic displacement with picometer precision — that’s the trillionths-of-a-meter scale crucial to understanding these promising nanoparticles... Link

2012

1. Akey, A.J., Lu, C., Wu, L., Zhu, Y., and Herman, I.P., “Anomalous photoluminescence Stokes shift in CdSe nanoparticle and carbon nanotube hybrids”, Phys. Rev. B 85, 045404 (2012).

2. Bo, S-H., Wang, F.,  Janssen, Y., Zeng, D.L., Nam, K-W.,  Xu, W.Q.,  Du, L-S.,  Stephens, P., Graetz, J., Yang, X-Q.,  Zhu, Y., Parise, J., Grey, C.,  and Khalifah, P., “Degradation and (De)lithiation Processes in the High Capacity Battery Material LiFeBO3”, J. Chem. Mater,  22 8799 (2012).

3. Chen, H., Hautier, G., Jain, A., Moore, C., Kang, B., Doe, R., Wu, L., Zhu, Y., Tang, Y., and Ceder, G., "Carbonophosphates: A New Family of Cathode Materials for Li-Ion Batteries Identified Computationally", Chem. Mater., 24, 2009-2016 (2012).

4. Chen, W.F., Sasaki, K., Ma, C., Frenkel, A.I., Marinkovic, N., Muckerman, J.T., Zhu, Y., and Adzic, R.R., “Hydrogen-Evolution Catalysts Based on Non-Nobel Metal Nickel-Molybdenum Nitride Nanosheets”, Angew. Chem. Int. Ed. 51 6131 (2012).

5. Ji H.; Allred J. M.; Ni N.; Tao J.; Neupane M.; Wray A.; Xu S.; Hasan M. Z.; and Cava R. J., “Bulk intergrowth of a topological insulator with a room-temperature ferromagnet”, Phys. Rev. B 85, 165315 (2012)

6. Nam, K.-W., Bak, S.-M., Hu, E., Yu, X., Zhou, Y., Wang, X., Wu, L., Zhu, Y., Chung, K.-Y., Yang, X.-Q., "Combining In Situ Synchrotron X-Ray Diffraction and Absorption Techniques with Transmission Electron Microscopy to Study the Origin of Thermal Instability in Overcharged Cathode Materials for Lithium-Ion Batteries", Adv. Funct. Mater. (2012).

7. Polking, M. J.,  Han, M.-G., Yourdkhani, A.,  Petkov, V., Kisielowski, C. F.,  Volkov, V.V.,  Zhu, Y., Caruntu, G., Alivisatos, A. P., and Ramesh, R.,“Ferroelectric order in individual nanometer-scale crystals”, Nature Materials, 11 700-709 (2012).

8. Pollard, S. D., Huang, L., Buchanan, K.S., Arena, D.A., Zhu, Y., “Direct Dynamic Imaging of Non-Adiabatic Spin Torque Effects”, Nature Communications, in press (2012).

9. Pollard, S.D., Volkov, V.V., and Zhu, Y., “Propagation of magnetic charge monopoles and Dirac flux strings in an artificial spin-ice lattice “, Phys. Rev. B (Rapid Comm. as Editors’ suggestions), 85, 180402(R) (2012).

10. Saucke, G., Norpoth, J., Jooss, Ch., Su, D., and Zhu, Y., “Polaron absorption for photovoltaic energy conversion in a manganite-titanate pn heterojunction”, Phys., Rev., B 85, 165315 (2012).

11. Tao J. “Nanoclusters in Magnetoresistance”, Nanotechnology Reviews, invited review article, in press.

12. Wu, L., Egerton, R.F., and Zhu, Y., “Image simulation for atomic resolution secondary electron image”, Ultramicroscopy, in press.

13. Xin, X., Zhou, X.F., Wang, F., Yao, X.Y., Xu, X.X., Zhu, Y., and Liu, Z.P., “A 3D Porous Architecture of Si/Graphene Nanocomposite as High-Performance Anode Materials for Li-Ion Batteries”, J. Mater. Chem., 22, 7724-7730 (2012).

14. Xu, Z., Hine, C.R., Maye, M.M., Meng, Q.P., and Cotlet, M., “Shell Thickness Dependent Photoinduced Hole Transfer in Hybrid Conjugated Polymer/Quantum Dot Nanocomposites: From Ensemble to Single Hybrid Level”, ACS Nano, 6 4984–4992 (2012).

15. Zeng, J., Zhu, C., Tao, J., Jin, M., Zhang, H., Li, Z.-Y., Zhu, Y., and Xia, Y., "Controlling nucleation and growth of silver on palladium nanocubes by manipulating the reaction kinetics" Angew. Chemie Int. Ed., 51, 2354-2358 (2012)

16. Zhang, Yu., Ma, C., Zhu, Y., Si, R., Cai, Y., Wang, J.X., Adzic, R.R., “Hollow core supported Pt monolayer catalysts for oxygen reduction”, Catalysis Today (in press).

17. Zhu, Y., Milas, M., Rameau, J., and Sfeir, M., "The Multimodal Optical Nanoprobe for Advanced Electron Microscopy", invited article, Microscopy Today, in press, 2012

18. Zhu, Y., and Wu, L., "Shadow Imaging for Charge Distribution Analysis", Book Chapter in “Electron Crystallography Meets Powder Diffraction”, U. Kolb, K. Shankland, L. Meshi, A. Avilov, and W. David Eds., Springer, in press.

19. Ma, C., Qin, Y., Yang, H., Tian, H., Li, J., Sardar, K.,, Walton, R.I., Su, D., Wu, L., and Zhu, Y., “Microstructure and oxidation states in multiferroic Lu2(Fe,Mn)3O7”, J. Appl. Phys., 094105 (2012).

20.  Neilson, J. R; Llobet A.; Stier A. V.; Wu L.; Wen J.; Tao J.; Zhu, Y.; Tesanovic Z. B.; Armitage N. P.; and McQueen M. T., “Mixed-valence-driven heavy-fermion behavior and superconductivity in KNi2Se2”, Phys. Rev. B 86, 054512 (2012) (highlighted as “Editors’ Suggestion”)

21. Norpoth, J., Su, D., Inada, H., Sievers, S., Zhu, Y., and Jooss, Ch., “Interfacial reconstruction and superconductivity in cuprate-manganite multilayers of YBa2Cu3O7 and Pr0.68Ca0.32MnO3”, New J, of Physics 14 093009 (2012).

22. Raabe, S., Mierwaldt, D., Ciston, J., Uijttewaal, M., Stein,H., Hoffmann, J., Zhu, Y., Blöchl, P., and Jooss, Ch., “In-situ electrochemical electron microscopy study of oxygen evolution activity of doped manganite perovskites", Advanced Functional Materials, DOI: 10.1002/adfm.201103173 (2012).

23. Schofield, M.A., He, J., Volkov, V.V., and Zhu, Y.,“Giant magneto-resistance estimated from direct observation of nanoscale ferromagnetic domain evolution in La0.325Pr0.3Ca0.375MnO3”, J. of Appl. Phys. 112, 053924 (2012).

24. Si, R., Tao, J., Evans, J., Park, B. J., Barrio, L., Hanson, J. C., Zhu, Y., Hrbek, J.,  and Rodriguez, J. A., “Effect of Ceria on Gold-Titania Catalysts for the Water-Gas Shift Reaction: Fundamental Studies for Au/CeOx/TiO2(110) and Au/CeOx/TiO2 Powders”, J. Phys. Chem. C, 116, 23547 (2012).

25. Tao, J., ”Nanoclusters in Magnetoresistance”, Nanotechnology Reviews, vol 1, issue 4, 301-311 (2012) (invited review article).

26. Wang, F., Yu, H.-C., Chen, M.H., Wu, L., Pereira, N., Thornton, K., Van der Ven, A., Zhu, Y., Amatucci, G.G., and Graetz, J., "Tracking lithium transport and electrochemical reactions in nanoparticles", Nature Communications, 3, 1201 (2012).

27. Xie, S., Jin, M., Tao, J., Wang, Y., Xie, Z., Zhu, Y., and Xia, Y., “Synthesis and characterization of Pd@MxCu1-x (M=Au, Pd, and Pt) nanocages with porous walls and a yolk-shell structure through galvanic replacement reactions”, Chemistry: A European Journal, 18, 14974-14980, (2012), (highlighted on the cover).

28. Zhu, C., Zeng, J., Tao, J., Johnson, M., Schmidt-Krey, I., Blubaugh, L., Zhu, Y., Gu, Z., and Xia, Y., “Kinetically controlled overgrowth of Ag or Au on Pd nanocrystal seeds: From hybrid dimers to non-concentric and concentric bimetallic nanocrystals”, J. of Am. Chem. Soc., 134, 15823 (2012).