Self-assembled Microcones Generated On Solid Surface Through Pulsed Laser Irradiation

Laser & Plasma Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India

Adv. Mater. Lett., 2013, Ion Beam Special Issue, 4 (6), pp 492-496

DOI: 10.5185/amlett.2012.ib.119

Publication Date (Web): Mar 16, 2013

Copyright © IAAM-VBRI Press

E-mail: ssinha@barc.gov.in

Abstract

We present here our results on surface micro-structuring via nanosecond pulsed laser irradiation of Titanium and Stainless Steel cathode samples. Laser based surface micro-structuring leading to formation of self-assembled micro-tips can potentially enhance field emission efficiency of such surface treated cathodes. Microstructure of the laser treated surfaces has been observed under a Scanning Electron Microscope (SEM) and SEM images were further analyzed using software attached with Optical Microscope. To study the effect of laser fluence on developed surface microstructure, the target surface was irradiated in different regions with laser beams at varying laser fluence levels ranging from 2-10 J/cm² for a period of 1 to 15 minutes corresponding to 600 to 9000 laser pulses. Mean height of the generated micro-cones was observed to increase from 17 to 30µm on increasing number of irradiating laser pulses from 3000 to 9000 in case of Stainless Steel samples. In case of laser treated Titanium average periodicity of generated self-assembled micro-cones decreased from 10.8μm to 6.5μm when laser fluence was increased from 5 to 10J/cm² with a total of 600 laser pulses used for irradiating the sample.

Keywords

Laser surface micro-structuring, self-aligned microcones, stainless Steel, titanium.