화학공학소재연구정보센터
Applied Surface Science, Vol.254, No.11, 3364-3369, 2008
A comparative study of gadolinium gallium garnet growth by femtosecond and nanosecond pulsed laser deposition
The growth of epitaxial Nd:Gd3Ga5O12 (GGG) on Y3Al5O12 (YAG) by femtosecond pulsed laser deposition is reported. We have used a Ti:sapphire laser at a wavelength of 800 nm and pulse length of 130 fs, operating at a repetition rate of 1 kHz. The film properties have been studied systematically as a function of the deposition parameters of laser fluence, spot-size, oxygen pressure, target-substrate distance and temperature. Scanning electron microscopy, atomic force microscopy and X-ray diffractometry were used to characterise the surface structure and crystallinity of the films. X-ray diffraction analysis shows that epitaxial growth has occurred. A comparison between the ion velocities produced by nanosecond and femtosecond laser ablation of the GGG target material has been investigated by the Langmuir probe technique. The results indicate a large difference in the plasma characteristics between femtosecond and nanosecond ablation, with ion velocities up to eight times faster observed in the femtosecond case. (c) 2007 Elsevier B. V. All rights reserved.