Infrared optical properties of Li- and Xe-irradiated KTiOPO4

• Published in: Applied physics. A, Materials science & processing Vol. 78; no. 4; pp. 589 - 596
• Main Authors: MAYERHÖFER, T. G, HÖCHE, T, SCHREMPEL, F
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.03.2004
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectrics; Exact sciences and technology; Fluence; Glassy; Inclusions; Infrared and raman spectra and scattering; Interference; Irradiation; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Physics; Simulation; Spectra; Radiation effects; Annealing; Inorganic compounds; Fluence; Ternary compounds; Refractive index; Transition element compounds; Titanyl Phosphates; Amorphous state; Potassium Phosphates; Infrared spectra; Experimental study; Ion beams; Thickness; Dielectric function; Transmission electron microscopy; Optical properties; Modelling; Effective medium model
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-003-2145-1

KTP was irradiated at 100 K and 295 K with Li ions and at 295 K with Xe ions. The infrared spectra of the Li-irradiated samples are consistent with a system consisting of a layer stack of undamaged KTP/amorphous KTP/undamaged substrate. Annealing of the samples leads to a growth of the covering layer at the expense of the amorphous layer. The damage yield of the sample irradiated at 100 K is noticeably higher, resulting in a greater thickness of the amorphous layer. The spectra show interference effects, indicating homogenous layer thicknesses. Such interference effects are absent for the Xe-irradiated samples. Spectral simulations revealed that there is no buried amorphous layer present in these samples. Instead, the latter samples consist of amorphous inclusions in undamaged crystalline KTP with a volume fraction depending on the energy dose. The spectra of the sample irradiated at an ion fluence of 3X10 cm are very similar to the spectrum of glassy KTP, indicating a strong structural relationship between ion-damaged amorphous KTP and glassy KTP. The dielectric function of amorphous KTP was determined and used, together with the principal dielectric functions of single-crystal KTP, to successfully simulate the spectra of a sample irradiated at an ion fluence of 2X10 cm by either the effective-medium approximation (EMA) or average-refractive-index theory (ARIT).