Z. Phys. Chem. 223 (2009) 1273–1284 . DOI 10.1524.zpch.2009.6079 © by Oldenbourg Wissenschaftsverlag, München Electrical Transport in Oxide Glasses Containing Gold Nanoparticles By Ahmed Issa 1,2 , Reiner Küchler 2 , Rajan V. Anavekar 1,‡ , Roland Böhmer 2 , Otmar Kanert 2 , and Himanshu Jain 1, * 1 Department of Materials Science and Engineering, Lehigh University, PA 18015, USA 2 Fakultät für Physik, Technische Universität Dortmund, 44221 Dortmund, Germany Dedicated to Prof. Dr. Klaus Funke on the occasion of his 65 th birthday (Received August 21, 2009; accepted September 24, 2009) Glass Structure . Electrical Conductivity . Nano-composites Gold doped ruby glasses are classical examples of metal-glass nanocomposites that have been investigated for their striking optical properties. For their multifunctional applications, we have explored the nature of the electrical response of two oxide glasses containing a small amount (<0.1mol%) of gold. Gold-doped lithium borate (LBO) and lanthanum borogermanate (LBGO) glasses are studied using ac conductivity as a function of frequency and temperature in relation to their structure as determined by electron microscopy. For ionically conducting LBO, Au doping produces a noticeable increase of the electrical conductivity. For poorly conducting LBGO, gold doping introduces a dielectric loss peak indicative of dipolar relaxation. The heat treatment of both glasses introduces a new mechanism of dc conduction or dipolar loss, which has about one third the activation energy of the untreated samples. This unexpected behavior is attributed to an ionic-to-electronic conductivity transition in gold doped glasses. 1. Introduction Nanoparticles of noble and transition metals such as Ag, Au, and Cu have been known for a long time [1], and they are currently attracting considerable renewed interest. Depending on their size and shape [2,3] these metallic particles can display electronic surface plasmon resonances in the visible spectral range which makes them interesting for a variety of optical devices, biosensors, etc. For some applications the nanocrystals are attached to surfaces [4,5], while for others they * Corresponding author. E-mail: h.jain@lehigh.edu ‡ Permanent address: Department of Physics, Bangalore University, Bangalore, 560 056, India. Brought to you by | New York University Bobst Library Technical Services Authenticated Download Date | 7/28/15 10:33 AM