The study of ultrafast dynamics behind a solid-state shock front using optical nanogauges

Photothermal laser ablation is studied using poly-(methyl methacrylate) films doped with a dye, IR-165, which functions as a molecular heater and thermometer. Direct optical measurements of temperature are performed on samples heated by 100 ns near-IR pulses at 1.064 μ\rm m, at rates dT/dt $\approx 5 \times 10\sp9$ deg/s. Below ablation threshold, the heat capacity measured by optical calorimetry is precisely the value obtained by conventional calorimetry. At ablation threshold, the peak surface temperature is $\rm T\sb{abl} = 600\sp\circ C$ and the weight-fraction of material decomposed at ablation time is $\chi\sb{th} = 0.02.$ With increasing pulse energy, the fraction decomposed increases and a more forceful ablation is observed, but the surface temperature does not continue to increase past $\rm T\sb{lim} = 715\sp\circ C,$ which is determined to be the limiting temperature for thermal decomposition.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Lee, I-Yin Sandy

Contributors dc:contributor

• Dlott, Dana D.

• Chemistry, Physical

Statement dc:rights

• Copyright 1995 Lee, I-Yin Sandy

Language dc:language

eng

Identifier

AAI9543643
(UMI)AAI9543643

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/20967