Optical properties of Ar ions irradiated nanocrystalline ZrC and ZrN thin films

• Published in: Journal of nuclear materials Vol. 488; pp. 16 - 21
• Main Authors: Martin, C., Miller, K.H., Makino, H., Craciun, D., Simeone, D., Craciun, V.
• Format: Journal Article
• Language: English
• Published: Goddard Space Flight Center Elsevier B.V 01-05-2017; Elsevier; Elsevier BV
• Subjects: Chemical bonds; Chemical compounds; Electronic properties; Fluence; Infrared optical properties; Insulators; Ion irradiation; Irradiation; Nanocrystalline films; Nanocrystals; Optical properties; Optics; Photoelectric emission; Pulsed laser deposition; Reflectance; Solid-State Physics; Spectroscopy; Spectrum analysis; Thin films; X ray photoelectron spectroscopy; Zirconium; ZrC; ZrN; ZrC; Pulsed laser deposition; Infrared optical properties; Nanocrystalline films; ZrN; Irradiated; Zrc; Infrared; Thin Films; Zrn; infrared optical properties; nanocristalline films; pulsed laser deposition
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2017.02.041

Employing wide spectral range (0.06–6 eV) optical reflectance measurements and high energy X-ray photoemission spectroscopy (HE-XPS), we studied the effect of 800 keV Ar ion irradiation on optical and electronic properties of nanocrystalline ZrC and ZrN thin films, which were obtain by the pulsed laser deposition technique. Both in ZrC and ZrN, we observed that irradiation affects the optical properties of the films mostly at low frequencies, which is dominated by the free carriers response. In both materials, we found a significant reduction in the free carriers scattering rate and an increase of the zero frequency conductivity, i.e. possible increase in mobility, at higher irradiation fluence. This is consistent with our previous findings that irradiation affects the crystallite size and the micro-strain, but it does not induce major changes in the chemical bonding. HE-XPS investigations further confirms the stability of the Zr-C and Zr-N bonds, despite a small increase in the surface region of the Zr-O bonds fraction with increasing irradiation fluence.