ISSN 1063-7842, Technical Physics, 2008, Vol. 53, No. 5, pp. 641–645. © Pleiades Publishing, Ltd., 2008. Original Russian Text © B.P. Gorshunov, M.L. Shupegin, V.Yu. Ivanov, A.S. Prokhorov, I.E. Spektor, A.A. Volkov, 2008, published in Zhurnal Tekhnicheskoœ Fiziki, 2008, Vol. 78, No. 5, pp. 111–115. 641 INTRODUCTION Diamondlike silicon–carbon films belong to a wide class of materials that are attracting ever increasing interest of researchers. This is because these films offer intriguing properties, such as simplicity and cheapness of their synthesis, good adhesion to many dissimilar materials (metals, oxides, crystalline and amorphous insulators, semiconductors, ceramics, and plastics), chemical and corrosion resistance, low residual elastic stresses, hardness, low friction coefficient, and environ- mental safety [1–3]. The possibility of controllably varying the electrical resistivity of the films by techno- logical means in a wide range, from 10 14 Ω cm (insula- tor) to 10 –4 Ω cm (“poor” metal), is also of great impor- tance. Such a set of properties makes these materials promising in various fields of technology. At the same time, their efficient application is limited, since system- atic knowledge of their fundamental physicochemical properties is virtually lacking. In this study, we pio- neered investigation of diamondlike films by optical spectroscopy, which is among the most powerful tools of experimental physics. EXPERIMENTAL Diamondlike silicon–carbon films are nanocompos- ites representing amorphous matrices (plasma-poly- merized polyphenylmethylsiloxane, PPMS) that con- tain nanoparticles of a foreign dissimilar material (met- als, such as Ti, Zr, Hf, Nb, Ta, Cr, Mo, W, etc., or alloys, such as NiCr, FeNiCr, etc.). Chromium/PPMS (Cr/PPMS) nanocomposite exhibits a maximal long- term stability of the properties and is the most resistant to environmental attack, which explains the choice of this material for investigation. Test Cr/PPMS samples were produced by simultaneous vacuum plasma depo- sition of PPMS vapor and magnetron sputtering of a chromium target [4]. We prepared two films on 1-mm- thick quartz substrates: one (film no. 1) had a thickness of 2000 Å, surface resistance of 35 Ω/, and weight content of chromium of 73%; the other (film no. 2) had a thickness of 2800 Å, surface resistance of 180 Ω/, and weight content of chromium of 54%. We also mea- sured the optical properties of PPMS free from metallic inclusions. For this purpose, we grew a 139-μm-thick PPMS sheet without substrate. For the metal-containing films, the static conductiv- ity in the temperature range 4.2–300 K was measured by the standard four-point probe technique. Optical measurements were performed in a wide frequency range using two spectrometers. In the sub- millimeter range (wavenumbers ν = 10–18 cm –1 or fre- quencies 300–540 GHz), we took noncontact measure- ments (5–300 K) of the spectra of dynamic conductiv- ity σ(ν), as well as of the real, ε'(ν), and imaginary, ε"(ν), parts of complex permittivity ε*(ν) = ε'(ν) + iε"(ν), of the films by the method detailed in [5, 6]. In a quasi-optical configuration, we measured transmission (Tr) spectra, phase shift ϕ of the wave having passed through the sample (the film on the substrate), and reflectance (R) spectrum. From the spectra, we directly calculated the spectra of “optical” characteristics of the films: ε'(ν), ε"(ν), σ(ν), etc. by applying the Fresnel formulas (see, for example, [7]) for one- and two-layer (a film on a substrate) media. The dielectric properties of the substrates were determined beforehand by mea- suring the substrates without films. IR measurements were carried out using a Bruker IFS 113V standard IR Fourier spectrometer in the wavenumber range 20–4000 cm –1 at room temperature. The transmission, Tr(ν), and reflectance, R(ν), spectra IR Spectroscopy of Diamondlike Silicon–Carbon Films B. P. Gorshunov, M. L. Shupegin, V. Yu. Ivanov, A. S. Prokhorov, I. E. Spektor, and A. A. Volkov Prokhorov General Physics Institute, Russian Academy of Sciences, ul. Vavilova 38, Moscow, 119991 Russia e-mail: gorshunov@ran.gpi.ru Received July 26, 2007 Abstract—IR spectra of metal-containing diamondlike silicon–carbon films are taken for the first time. It is shown that the optical response from the subsystem of free charge carriers in chromium-containing films can be described in terms of a simple model that deals with carriers localized inside clusters several nanometers in size. The data obtained indicate that the electric and dielectric properties of the films can be controlled by tech- nological means during their synthesis and by varying the size, concentration, and conductivity of metallic nan- oclusters. PACS numbers: 77.84.Lf, 78.67.-n DOI: 10.1134/S1063784208050186 SURFACE, ELECTRON AND ION EMISSION