CC BY
9LM-P-1
Luminescent Ce-based nanoparticles embedded into polycrystalline diamond matrix: synthesis and optical properties
V. Sedov1, S. Kuznetsov1, I. Kamenskikh2, A. Martyanov1, D. Vakalov3, V. Konov1
1Prokhorov General Physics Institute of the Russian Academy of Sciences, Vavilov str. 38, Moscow, Russia 2 Physics Faculty of Lomonosov Moscow State University, 1-2 Leninskiye Gory GSP-1, Moscow, Russia 3 North Caucasus Federal University, Kulakov Prosp. 2, Stavropol, Russia
Free-electron lasers allow the generation of coherent electromagnetic radiation in the X-ray range with very high peak power. Thus, there are new challenges in fabricating detectors and visualizers for the "hard" high-power radiation. Diamond is a perfect candidate for the role of X-ray transparent matrix not only due to low X-ray absorption but also due to its high thermal conductivity and chemical/radiation resistance.
Our approach is based on the integration of yttrium-aluminum or gadolinium-aluminum garnets doped with cerium (YAG:Ce and GAG:Ce, accordingly) in form of nanoparticles into robust and X-ray-transparent diamond matrix [1-4]. The solid garnet solutions were synthesized by co-precipitation from aqueous solution technique. Polycrystalline diamond films were grown in microwave plasma in the CVD reactor ARDIS-100. The thickness of composite films was in the range of 3-10 microns with a lateral size of up to 2 inches. The structure and properties of initial powders and obtained composites were studied by scanning electron microscopy, X-ray diffraction patterns, photoluminescence and X-ray luminescence.
The composite films show high-intensity X-ray luminescence with broadband peak at 550 nm (5d ^ 4f transition in Ce3+ ion), and a narrow peak of silicon-vacancy (Si-V) centers at 738 nm. The characteristic decay time was measured at ioe<50 ns for cerium emission and at TSiV~1 ns for Si-V centers.
The proposed composite material may be engineered to show XRL of desired intensity: from low intensities for high-power free-electron lasers up, which allows preserving the energy of the incident X-ray beam, to high intensities for sensitive X-ray detectors. Thus, the luminescent diamond composites suggest a new way to control X-ray visualization for fast X-ray detectors and screens. The reported study was funded by RFBR, project №20-32-70074.
Figure 1. X-ray luminescence mechanism in diamond composites.
[1] V.S. Sedov, S.V. Kuznetsov, V.G. Ralchenko et al. Diam. Relat. Mater. 72, 47 (2017).
[2] V. Sedov, S. Kouznetsov, A. Martyanov et al. ACS Appl. Nano Mater. 3, 1324 (2020).
[3] S.V. Kuznetsov, V.S. Sedov, A.K. Martyanov et al. Ceram. Inter. 47, 13922 (2021).
[4] V. Sedov, S. Kuznetsov, I. Kamenskikh et al. Carbon 174, 52 (2021).
sedovvadim @yandex. ru
c@3+
mm
^ Si-V 738 nm
