Nanocomposites and nanomaterials
The percussive nanosecond laser synthesis of new carbon nitride phases on nanocolonar carbon nitride films-targets
Budnyk O.P.1, Prudnikov A.M 2, Fesenko O.M.1, Pashkevich Yu.G.2, Dmitrenko V. Yu. 2, and Pas'ko M.I.2
1 Transfer Technology Department, Institute of Physics of the NAS of Ukraine, prospect Nauky, 46, Kyiv-03028, Ukraine. 
E-mail: oksana.urc@gmail.com, anatoliy.prudnikov@hotmail.com
2 Donetsk Institute for Physics and Engineering named after O.O. Galkin of the NAS of Ukraine, prospect Nauky, 46, Kyiv-03028, Ukraine.

Diamond-like carbon (DLC) is a wide band gap semiconductor material with a high mechanical hardness, chemical inertness, and optical transparency [1]. DLC is a metastable form of amorphous carbon with a significant fraction of sp3-bonding. Since it is much cheaper to produce than diamond itself, DLC is commonly employed as protective coating in magnetic storage disks, optical windows and micro-mechanical devices. The real growth in applications has occurred for doped or interlayer-modified variants of DLC. 
In the last decade, carbon nitrides has been received much attention due to potential applications in tribology and electrochemistry. Since theoretical prediction of low compressibility materials with C3N4 composition [2], many efforts have been devoted to the synthesis of carbon nitrides [3]. For instance, C2N were synthesized by shock compression of C3N2 in a pressure-temperature dynamic range of about 30 GPa ‒ 3000 K [4]. However, with yield of 8% a small quantity of product was obtained causing difficulties for further characterization.
Earlier we reported on the synthesis of C2N structures from the CNx:H films by the adiabatic annealing with a short (tp = 10 ns) and intense (0.1 GW/cm2) Nd3+:YAG laser (λ = 1.064 μm) pulses [5]. Here we report on the effect of pulsed laser irradiation on the structural properties of nanocolumnar CNx:O films, where resulting C2N microcrystals were studied by SEM and Raman spectroscopy.

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5.	А. Prudnikov, Y. Pashkevich, K. Lamonova, V. Uvarov and M. Pas’ko, Formation of New Nanostructures and Their Optical Properties under the Influence of High Pressure and Laser Irradiation // IEEE 9th International Conference Nanomaterials: Applications & Properties (NAP), 2019. ‒ P. 1‒4.