Metallized thiazolylazo dyes as optical recording materials

A series of metallized thiazolylazo dyes have been designed and synthesized. Smooth films on optical glass and single-crystal silicon were prepared using the spin-coated method. The UV-Vis absorption spectra of the dyes were measured in solution and in films. The optical constant (complex refractive index N=n+ik) of the films on single-crystal silicon has been determined using a scanning ellipsometer. The variation of the complex refractive index, N, with wavelength, λ, was obtained. From the value of n, k and the thickness of the dye films, the variation of the reflectance vs dye film thickness was then calculated. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) of the nickel thiazolylazo dye showed a clear threshold of thermal decomposition with a sharp exothermic park. Static optical recording tests were carried out. The results show that the nickel thiazolylazo dye is more suitable for use in short-wavelength diode-laser optical recording.