Abstract
Controlling laser-pulse parameters is an important issue in pulsed laser
deposition (PLD). In particular, homogenization of laser beams improves
the reproducibility of the PLD process by guaranteeing a uniform
intensity distribution and a well-defined energy density of the laser
spot on the target. We have integrated a beam-homogenization system into
our PLD setup, and here we discuss the results and advantages of using
such a system. The optical setup is based on diffractive beam-splitter
gratings, which produce a 2×2-mm2 flat-top distribution with fluences of the order of 3 J/cm2
on the target. We demonstrate the applicability of this technique by
depositing thin films of ferromagnetic Ni–Mn–Ga shape-memory alloys.
Magnetic and structural characterization, including secondary ion mass
spectrometry (SIMS), indicate that nearly stoichiometric composition and
crystallization in the desired martensitic phase is obtained for films
deposited on Al2O3 under optimal conditions. In contrast, the formation of silicide compounds at temperatures above 500 ∘C is detrimental in the deposition of Ni–Mn–Ga films directly on silicon.
Original language | English |
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Pages (from-to) | 423-430 |
Number of pages | 8 |
Journal | Applied Physics A: Materials Science and Processing |
Volume | 108 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2012 |
MoE publication type | A1 Journal article-refereed |