Recent results on high-power pulsed-laser-induced transformations at liquid-solid interface are described in the context of synthesis of new metastable phases of materials. Specifically two types of problems are reported: (i) laser-induced synthesis of compound film at liquid solid interface, this process being termed “reactive quenching”, and (ii) laser-induced alloying of layered structure under liquid medium wherein the reactive aspect plays the minimal role. So far the reactive quenching process has been studied for different metals, compounds and thin film sandwiches in various liquid ambients such as H2O, liquid ammonia (NH3), liquid N2 and benzene (C6H6). The identification of the metastable phases and the microstructural transformations therein subsequent to laser processing and thermal annealing have been brought out by employing a range of techniques such as conversion electron Mössbauer spectroscopy (CEMS), X-ray diffraction (XRD), Rutherford backscattering spectrometry (RBS), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), etc. Laser-induced alloying of layered structure in liquid ambient has been investigated in case of Fe/Al and Fe/B systems. The possible mechanism which could be responsible for the observed effects is discussed on the basis of time-resolved reflectivity measurements.
Volume 42 | Issue 6
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