Exchange bias and the origin of magnetism in Mn-doped ZnO tetrapods

Zheng, R.K., Liu, H., Zhang, X.X., Roy, V.A.L. and Djurišić, A.B. (2004) Exchange bias and the origin of magnetism in Mn-doped ZnO tetrapods. Applied Physics Letters, 85(13), pp. 2589-2591. (doi: 10.1063/1.1795366)

Abstract

Wurtzite-type ZnO tetrapod nanostructures were prepared by evaporating Zn metal under humid argon flow. After the fabrication, Mn was doped into ZnO nanostructures by diffusion at 600 °C. The average concentration of Mn was determined to be 8.4 mol % by x-ray fluorescence. X-ray diffraction patterns obtained from the doped and undoped samples are almost the same. High-resolution transmission electron microscopy observations reveal the existence of surface layers. Magnetic measurements show that the sample has a very large coercivity HC=5500 Oe at 5.5 K and a Curie temperature TC=43 K, which may suggest that ferrimagnetic sZn,MndMn2O4 exists at the surface. Exchange bias is clearly observed below 22 K. Exchange bias is attributed to the exchange interaction between ferrimagnetic sZn,MndMn2O4 and spin-glass-like (or antiferromagnetic) phase in manganese oxides.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Vellaisamy, Professor Roy
• Authors: Zheng, R.K., Liu, H., Zhang, X.X., Roy, V.A.L., and Djurišić, A.B.
• College/School: College of Science and Engineering > School of Engineering
• Journal Name: Applied Physics Letters
• Publisher: AIP Publishing
• ISSN: 0003-6951
• ISSN (Online): 1077-3118
• Published Online: 28 September 2004