Regular papers

The effect of nanoparticle size on thermal diffusivity of gold nano-fluid measured using thermal lens technique

¹ Department of Physics, Faculty of Science, Shahrekord University, P.O. Box 115, Shahrekord, Iran
² Department of physics, Universiti Putra Malaysia, 43400UPM Serdang, Malaysia
³ Department of Materials Engineering and Ceramic, CICECO, University of Aveiro, Campus Santiago, 3810-193 Aveiro, Portugal

^* esmaeil.phy@gmail.com

Received: 10 October 2012
Revised: 27 February 2013

Abstract

A dual beam mode-mismatched thermal lens method has been employed to investigate the dependence of thermal diffusivity of gold nanofluid on nanoparticles sizes. The samples were prepared at various sizes by utilizing the gamma radiation method. In the dual beam mode-mismatched thermal lens a diode laser (532 nm) was used as an excitation beam and a He-Ne laser with the beam output at 632.8 nm was used as a probe beam. Thermal diffusivity of gold nano-fluid increased with the increasing particle sizes ranging from 10.4 to 29.6 nm.