Method for the preparation of photochromic insulating crystals

Patent · Wed Jan 01 00:00:00 EST 1986

OSTI ID:865774

Abraham, Marvin M ^[1]; Boldu, Jose L ^[2]; Chen, Yok ^[1]; Orera, Victor M ^[3]

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1. Oak Ridge, TN
2. Mexico City, MX
3. Zaragosa, ES

A method for preparing reversible-photochromic magnesium oxide (MgO) crystals. 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.degree. K. in a hydrogen atmosphere. Alternate irradiation with UV and visible light result in rejuvenation and bleaching of the amber coloration, respectively.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• DOE Contract Number: W-7405-ENG-26
• Assignee: United States of America as represented by Department of Energy (Washington, DC)
• Patent Number(s): US 4572618
• OSTI ID: 865774
• Country of Publication: United States
• Language: English

Related Subjects

method
preparation
photochromic
insulating
crystals
preparing
reversible-photochromic
magnesium
oxide
mgo
single
doped
lithium
nickel
grown
conventional
fusion
as-grown
characterized
amber
coloration
lose
thermochemically
reduced
heating
temperatures
1000
degree
hydrogen
atmosphere
alternate
irradiation
visible
light
result
rejuvenation
bleaching
respectively
chemically reduce
visible light
single crystal
single crystals
magnesium oxide
hydrogen atmosphere
fusion method
chemically reduced
/359/117/423/501/