AVS 51st International Symposium
    Magnetic Interfaces and Nanostructures Thursday Sessions
       Session MI-ThM

Paper MI-ThM10
Characterization of Transition Metal Doped ZnO Films and Nanostructures

Thursday, November 18, 2004, 11:20 am, Room 304A

Session: Magnetic Oxides and Half-Metallics
Presenter: D.H. Hill, Rutgers University
Authors: D.H. Hill, Rutgers University
L. Wielunski, Rutgers University
D.A. Arena, Brookhaven National Lab
R. Bartynski, Rutgers University
P. Wu, Rutgers University
Y. Lu, Rutgers University
Correspondent: Click to Email
A crucial element for the success of spintronics is finding a material that combines the desirable properties of ferromagnets and semiconductors. Diluted magnetic semiconductors (DMS) are intriguing materials that offer the possibility of studying magnetic phenomena in crystals with a simple band structure and excellent magneto-optical and transport properties. ZnO, a wide bandgap (~3.3 eV) semiconductor that has received increasing attention due to its broad applications and its many desirable material properties, has recently has been identified as a promising DMS candidate for room temperature spintronics. We have characterized the chemical, compositional, and magnetic properties of TM-doped ZnO films grown by MOCVD and sputter deposition on a variety of substrates. Doping with Mn, and Fe by either diffusion, co-sputtering, or ion implantation has been investigated, and each doping method results in very different dopant depth profiles as revealed by Rutherford backscattering spectrometry. Soft x-ray absorption spectroscopy (SXAS) indicates that the TM dopant may be in either the 2+ or 3+ oxidation state and depends upon doping method. Furthermore, the XAS results are consistent with the TM ions being substitutional for Zn. Squid magnetometry shows that some doping methods yield films exhibiting ferromagnetic behavior, with some Fe-doped films having the Curie temperatures above room temperature. Finally, we discuss the properties of MOCVD-grown ZnO nanotips that have been doped by TM ion implantation.