Variation of the refractive index and polarizability of sapphire under high-pressures

• Published in: Journal of applied physics Vol. 73; no. 3; pp. 1426 - 1429
• Main Authors: BALZARETTI, N. M, DENIS, J. P, DA JORNADA, J. A. H
• Format: Journal Article
• Language: English
• Published: Woodbury, NY American Institute of Physics 01.02.1993
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; 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; Polarizability; Refraction index; Experimental study; Density; Pressure; Inorganic compound; Aluminium Oxides; Sapphire; Volume; Hydrostatic pressure; Diamond anvil; Semiempirical method; Vibrational mode; Interferometry
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.353240

In this article we present the experimental results for the pressure variation of the refractive index of sapphire up to 16 GPa, obtained with an interferometric method, using the diamond anvil cell. In the range of hydrostatic pressures, up to about 12 GPa, the analysis of the results with the classic Lorentz–Lorenz approach provides a nearly linear relation between polarizability (α) and volume, corresponding to a constant strain polarizability parameter. For pressures above 12 GPa, there is a substantial nonlinear deviation, associated with nonhydrostatic effects inside the diamond anvil cell.