Z. John Zhang Professor Office: MS&E 1100N Phone: 404-894-6368 Fax: 404-894-7452 E-mail Z. John Zhang

B.S., Fudan University, 1984; Ph. D., University of Wisconsin-Madison, 1993; Postdoctoral fellow at Harvard University

Alfred P. Sloan Research Fellow - 2002; Presidential Early Career Award for Scientists and Engineers (PECASE) - 2001; DOE- Defense Programs Early Career Scientist and Engineer Award - 2001; ACS ExxonMobil Award in Solid State Chemistry - 2000; Beckman Foundation Young Investigator Award - 1999; Sigma-Xi Young Faculty Award - 1999; NSF CAREER Award - 1999

Research Interests

The research interests of Dr. Zhang and his group focus on understanding the fundamental relationships between the chemical composition/crystal structure and the properties of novel materials. A multidisciplinary approach including inorganic/physical chemistry and solid-state physics is employed to pursue the synthesis and physical property studies of nanostructured materials. The applications of these materials in advanced technologies and in biomedical science are also actively explored.

The current research focus of Zhang's group is on the synthesis and characterization of magnetic metal oxide nanoparticles with an emphasis on chemically controlling magnetic properties. The specific goal is to understand, at the atomic level, the physical properties of magnetic solids through the systematic studies of chemical composition, structure, and coordination chemistry. The fundamental issue in magnetic materials studies is the effect of magnetic couplings that include the electron spin-spin, electron spin-orbital, and interparticle magnetic moment couplings. The relationships between the macroscopic magnetic properties and the microscopic magnetic couplings are not yet well understood. Zhang's group is examining the contribution of various magnetic couplings to macroscopic magnetic properties by utilizing crystal chemistry to rationally control the magnitude of coupling components and the geometric length scales of the couplings.

The research in Zhang's group provides a wide range of opportunities for graduate students to learn both synthetic techniques and state-of-the-art characterization methods including solution and solid-state chemistry synthesis, X-ray and neutron diffraction, transmission electron microscopy, Magneto-optical spectroscopy, fluorescence microscopy, Mossbauer spectroscopy, and SQUID magnetometry.

Recent Publications

"Correlation between Spin-Orbital Coupling and the Superparamagnetic Properties in Magnetite and Cobalt Ferrite Spinel Nanocrystals," Qing Song and Z. John Zhang, J. Phys. Chem. B, 2006, 110, 11205-11209.

"Expanding the utility of one-pot multistep reaction networks through compartmentation and recovery of the catalyst, Nam T. S. Phan, Christopher S. Gill, Joseph V. Nguyen, Z. John Zhang and Christopher W. Jones, Angew. Chem., Int. Ed., 2006, 45, 2209-2212.

"Impact of manganese incorporation on the structural and magnetic properties of MOCVD-grown Ga1-xMnxN," Matthew H. Kane, Ali Asghar, Martin Strassburg, Qing Song, Adam M. Payne, Christopher J. Summers, Z. John Zhang, Nikolaus Dietz and Ian T. Ferguson, Mater. Res. Soc. Symp. Proc., 2005, 831, 515-520.

"Correlation of the structural and ferromagnetic properties of Ga₁-xMnxN grown by metalorganic chemical vapor deposition," Matthew H. Kane, Martin Strassburg, William E. Fenwick, Ali Asghar, Adam M. Payne, Shalini Gupta, Qing Song, Z. John Zhang, Nikolaus Dietz, Christopher J. Summers and Ian T. Ferguson, J. Cryst. Growth, 2006, 287, 591-595.

"Alloying, co-doping, and annealing effects on the magnetic and optical properties of MOCVD-grown Ga1-xMnxN," Matthew H. Kane, Martin Strassburg, Ali Asghar, William E. Fenwick, Jayantha Senawiratne, Qing Song, Christopher J. Summers, Z. John Zhang, Nikolaus Dietz and Ian T. Ferguson, Mater. Sci. Eng., B, 2005, 126, 230-235.

"Multifunctional III-nitride dilute magnetic semiconductor epilayers and nanostructures as a future platform for spintronic devices," Matthew H. Kane, Martin Strassburg, Ali Asghar, Qing Song, Shalini Gupta, Jayantha Senawiratne, Christoph Hums, Ute Haboeck, Axel Hoffmann, Dmitry Azamat, Wolfgang Gehlhoff, Nikolaus Dietz, Z. John Zhang, Christopher J. Summers and Ian T. Ferguson, Proc. SPIE-Int. Soc. Opt. Eng., 2005, 5732, 389-400.

"Effects of interparticle interactions upon the magnetic properties of CoFe₂O₄ and MnFe₂O₄ nanocrystals," C. R. Vestal, Q. Song, Z. J. Zhang, J. Phys. Chem. B, 2005, 108, 18222-18227.

"Faraday rotation in Co0.85Zn0.15Fe₂O₄ spinel ferrite nanoparticulate films under low applied fields," R. M. Anderson, C. R. Vestal, A. C. S. Samia, Z. J. Zhang, Appl. Phys. Letts., 2004, 84, 3115-3117.

"Shape control and associated magnetic properties of spinel cobalt ferrite nanocrystals," Q. Song, Z. J. Zhang, J. Am. Chem. Soc., 2004, 126, 6164-6168.

"Quantum couplings and magnetic properties of CoCrxFe₂-xO₄ (0 < x < 1) spinel ferrite nanoparticles synthesized with reverse micelle method," M. Han, C. R. Vestal, Z. J. Zhang, J. Phys. Chem. B, 2004, 108, 583-587.

"Synthesis and magnetic characgerization of Mn and Co spinel ferrite-silica nanoparticles with tunable magnetic core," C. R. Vestal, Z. J. Zhang, Nano Letts., 2003, 3, 1739-1743.

"Normal micelle synthesis and characterization of MgAl₂O₄ spinel nanoparticles," C. R. Vestal, Z. J. Zhang, J. Sol. St. Chem., 2003, 175, 59-62.

"Effects of surface coordination chemistry on the magnetic properties of MnFe₂O₄ spiinel ferrite nanoparticles," C. R. Vestal, Z. J. Zhang, J. Am. Chem. Soc., 2003, 125, 9828-9833.