Far-infrared properties of two-level systems in amorphous ice

• Published in: Europhysics letters Vol. 53; no. 1; pp. 40 - 45
• Main Authors: Agladze, N. I, Sievers, A. J
• Format: Journal Article
• Language: English
• Published: Les Ulis IOP Publishing 01.01.2001; EDP Sciences; EDP sciences
• Subjects: 63.50.+x; 78.30.Ly; 78.90.+t; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Disordered solids; Exact sciences and technology; Infrared and raman spectra and scattering; Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity); Optical constants: refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Physics; Inorganic compounds; Two-level systems; Theoretical study; Ice; Amorphous state; Infrared spectra; Optical density
• ISSN: 0295-5075; 1286-4854
• DOI: 10.1209/epl/i2001-00121-4

Isotopic substitution and defect doping have been used to alter the optical properties of two-level systems (TLS) in the two amorphous phases of a-$\ab{H}_2\ab{O}$ ice. A large TLS optical density of states is found for a-$\ab{H}_2\ab{O}$ and a-HOD in the high-density amorphous phase while a thirty times smaller value occurs for both in the low-density amorphous one. Our quantitative spectroscopic and thermal study bring out a number of new features, among them that LiCl doping of low-density amorphous ice increases its TLS optical density of states, its glass transition temperature and its fragility.