Photochromic and/or cathodochromic sodalite material, method of its preparation, and sensing element of a variable light transmission device manufactured from such material

US4490286A · kind A · utility

Assignee

• Institut Fiziki Akademii Nauk Estonskoi SSR · EE

Inventors

• Filipp K. Volynets · Las Piñas, PH
• Vladimir Demidenko · Las Piñas, PH
• Roman Denisov · Ludwigsburg, DE
• Viktor P. Denx · Tartu, EE
• Alexandr E. Dydelzak · Tartu, EE
• Engels N. Ryzhikov · Las Piñas, PH
• Evgenia A. Terentieva · Las Piñas, PH

Key dates

• Filing date: Dec 14, 1981
• Grant date: Dec 25, 1984
• Expiry date: Dec 14, 2001

Classification

• Technology area (CPC G): Physics
• CPC primary: G03C1/725
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A photochromic and/or cathodochromic sodalite material according to the invention represents a transparent monolith with a homogeneous polycrystalline structure and has a density in excess of 99% of the theoretical density of sodalite with an identical chemical composition. Such material is prepared by hot moulding of the sodalite powder obtained by any method under conditions preventing intense evaporation of alkali halides and incongruent melting of the sodalite. The sensing element of the prepared material is made in the form of a plate with its thickness chosen according to the desired sensitivity of radiation registration and the desired contrast ratio of the image stored as the sensing element is in transparent mode of operation.