Method for the preparation of photochromic insulating crystals
Abstract
A method for preparing reversible photochromic magnesium oxide (MgO) crystals is disclosed. Single crystals of MgO doped with both lithium (Li) and nickel (Ni) are grown by a conventional arc fusion method. The as grown crystals are characterized by an amber coloration. The crystals lose the amber coloration and become photochromic when they are thermochemically reduced by heating at temperatures greater than 1000(0)R in a hydrogen atmosphere. Alternate irradiation with UV and visible light result in rejuvenation and bleaching of the amber coloration, respectively.
- Publication:
-
Patent Application Department of Energy
- Pub Date:
- September 1984
- Bibcode:
- 1984doe..reptQ....A
- Keywords:
-
- Crystal Growth;
- Heat Treatment;
- Insulation;
- Light (Visible Radiation);
- Magnesium Oxides;
- Photochromism;
- Ultraviolet Radiation;
- Bleaching;
- Doped Crystals;
- Hydrogen;
- Lithium;
- Nickel;
- Reduction (Chemistry);
- Single Crystals;
- Electronics and Electrical Engineering