Document Type
Thesis
Date of Award
2025
Degree Name
Master of Science (MS)
Department
Chemistry
First Advisor
Chaoyang Jiang
Abstract
Luminescent materials have been extensively studied for a wide range of applications such as anti-counterfeiting, light emitting devices, and bioimaging. Among various host matrices, zinc germanate (ZGO), an inorganic material composed of ZnO4 and GeO4 tetrahedra, is commonly used due to its excellent thermal stability and luminescent tunability. ZGO can be synthesized using either solid-state reactions or hydrothermal methods. However, many of these methods are energy-intensive, time-consuming, or require harsh conditions. In contrast, ball milling offers a more time- and energy-efficient method as a part of mechanochemical syntheses. In this work, we developed a new synthetic method for ZGO phosphor materials using a ball milling process. By optimizing parameters such as milling speed, duration, environment, and grinding to sample media mass ratio, we produced manganese doped ZGO phosphors with strong green fluorescence and phosphorescence. The crystalline structures were confirmed using powder X-ray diffraction and luminescent properties were measured with fluorescence spectrophotometry. To further enhance luminescent performance, post-synthesis annealing in a muffle furnace was explored. Additionally, we found that altering dopant concentration allows for precise tuning of the luminescence properties, which facilitates the use of these ZGO phosphors as a new pigment for data encryption. Using these pigments, we successfully fabricated covert 2D data matrices that can only be decoded under specific UV excitation. With additional optimization, ZGO phosphor-based pigments show excellent potential for next-generation functional materials in security applications.
Subject Categories
Chemistry | Inorganic Chemistry
Keywords
Ball Milling Luminescence Mechanochemistry Phosphor Materials
Number of Pages
71
Publisher
Uiversity of South Dakota
Recommended Citation
Burmood, Zachary, "MECHANOCHEMICAL SYNTHESIS OF GERMANATE PHOSPHORS FOR LUMINESCENCE-BASED DATA ENCRYPTION" (2025). Dissertations and Theses. 371.
https://red.library.usd.edu/diss-thesis/371