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 luminescent borate formed from a borate having a crystal structure and including a first substitutable element and a second substitutable element;
wherein the luminescent borate comprises one or more rare earth ions substituted for the first substitutable element, wherein the one or more rare earth ions are selected from a group consisting of neodymium and ytterbium; and
wherein the luminescent borate further comprises chromium substituted for the second substitutable element.
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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 and a second substitutable element, one or more rare earth ions substituted for the first substitutable element, and chromium substituted for the second substitutable element. The one or more rare earth ions are selected from a group consisting of neodymium and ytterbium. 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
20 Claims
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1. A luminescent material comprising:
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a luminescent borate formed from a borate having a crystal structure and including a first substitutable element and a second substitutable element; wherein the luminescent borate comprises one or more rare earth ions substituted for the first substitutable element, wherein the one or more rare earth ions are selected from a group consisting of neodymium and ytterbium; and wherein the luminescent borate further comprises chromium substituted for the second substitutable element. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method for producing a luminescent material for use in authentication, the method comprising the steps of:
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preparing a luminescent borate from a borate having a crystal structure and including a first substitutable element and a second substitutable element, wherein preparing the luminescent borate comprises; substituting one or more rare earth ions for the first substitutable element of the borate, and substituting chromium for the second substitutable element of the borate, wherein the one or more rare earth ions are selected from a group consisting of neodymium and ytterbium; and dispersing the luminescent borate in a medium to produce the luminescent material. - View Dependent Claims (14, 15, 16)
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17. An article comprising:
a security feature that includes; a medium, and particles of a luminescent borate dispersed in the medium, the luminescent borate formed from a borate having a crystal structure and including a first substitutable element and a second substitutable element, wherein the luminescent borate comprises one or more rare earth ions substituted for the first substitutable element, wherein the luminescent borate further comprises chromium substituted for the second substitutable element, and wherein the one or more rare earth ions are selected from a group consisting of neodymium and ytterbium. - View Dependent Claims (18, 19, 20)
Specification