METHOD FOR PRODUCING HEAT-SENSITIVE NANOCOMPOSITE PHOTON CRYSTALS

摘要

The invention relates to methods for producing composite materials, in particular nanocomposite photon crystals on the basis of opal matrices, with the option of changing the width of the photon inhibited zone. The problem addressed by the invention consists in developing a method for producing nanocomposite photon crystals on the basis of opal with a photon inhibited zone controlled by means of changing the temperature of the surrounding medium - it can find application as temperature sensors for fiber optic systems. In the method for producing nanocomposite materials on the basis of an opal structure of a photon crystal, which method comprises introducing materials into the opal matrix, the materials used therefor are cholesteric liquid crystals introduced by impregnation under pressure and at a temperature higher than the temperature for the transition of the liquid crystal to the isotropic state. The method for forming heat-sensitive nanocomposite photon crystals with a changeable photon inhibited zone controlled by means of the external temperature consists in introducing a material with changeable properties depending on the external temperature into the opal structure obtained by etching of colloidal particles forming a crystal lattice of the photon crystal with the introduced opal, which is introduced by a method of opal oxide precursor infiltration. The method is characterized in that the initial structure for the photon crystal is formed by polystyrene particles using a procedure for deposition on a flat substrate. Opal oxide precursor infiltration into the initial opal structure is held at a pressure from 1.2 to 1.5 times higher than the atmospheric pressure and at a temperature from 60 to 80°C. The introduced material with changeable properties depending on the external temperature that is used is a mesomorphic substance in the form of a cholesteric liquid crystal which is introduced by impregnation at a temperature that is greater than the temperature for the transition of the liquid crystal to the isotropic state (from 70°C) and at a pressure from 150 to 200 kPa, followed by the final step of coating the surface of the photon crystal with a metal layer having a width from 150 to 300 nm by magnetron sputtering at a speed from 20 to 40 nm/min. This step is necessary for improving the structure stability in case of heating.