Luminescent borates, materials and articles incorporating such borates, and methods and apparatus for their production and use in article authentication
First Claim
1. A luminescent material comprising:
- a borate having a crystal structure and including a substitutable element;
neodymium substituted for the substitutable element at a first substitution percentage of at least about 20 percent; and
ytterbium substituted for the substitutable element at a second substitution percentage.
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Accused Products
Abstract
Embodiments include luminescent materials and associated production methods. The material includes a crystal borate having a first substitutable element, neodymium substituted for the first substitutable element at a first substitution percentage of at least about 20 percent, and ytterbium substituted for the first substitutable element at a second substitution percentage. The material also may include chromium substituted for a second substitutable element. The material also may include a medium within which particles of the borate are incorporated. The medium, with the luminescent material particles, may form a security feature of an article. Embodiments of methods for identifying whether such a luminescent material is incorporated with an article include exposing a portion of the article to excitation in a chromium absorption band, and determining whether a detected emission produced by the article as a result of the excitation indicates an ytterbium emission after termination of the exposing step.
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Citations
15 Claims
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1. A luminescent material comprising:
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a borate having a crystal structure and including a substitutable element; neodymium substituted for the substitutable element at a first substitution percentage of at least about 20 percent; and ytterbium substituted for the substitutable element at a second substitution percentage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. An article comprising:
a security feature that includes; a medium, and particles of a luminescent borate dispersed in the medium, the luminescent borate comprising a borate having a crystal structure and including a substitutable element, neodymium substituted for the substitutable element at a first substitution percentage of at least about 20 percent, and ytterbium substituted for the substitutable element at a second substitution percentage. - View Dependent Claims (13, 14, 15)
Specification