LUMINESCENT BORATES, MATERIALS AND ARTICLES INCORPORATING SUCH BORATES, AND METHODS AND APPARATUS FOR THEIR PRODUCTION AND USE IN ARTICLE AUTHENTICATION

摘要

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.