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Updated: Jul 27, 2025
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Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
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Study on Local-Structure Symmetrization of K
Mega Novita1, Sigit Ristanto2, Ernawati Saptaningrum2
1Postgraduate Program of Science Education, Universitas PGRI Semarang, Semarang 50232, Indonesia.
Materials (Basel, Switzerland)
|June 10, 2023
Summary
This study explores how local structural symmetrization affects the luminescence of Mn4+-activated red phosphors. Decreased Mn-F bond length and lower symmetry reduce electron-electron repulsion, impacting luminescence properties.
Area of Science:
- Materials Science
- Solid-State Chemistry
- Luminescence
Background:
- Mn4+-activated fluorides, particularly A2XF6: Mn4+ and BXF6: Mn4+ compounds, are well-established red phosphors.
- Their luminescence performance is critically dependent on the local crystal structure surrounding the dopant ions.
- Previous research has not investigated the specific impact of local structural symmetrization on red phosphor luminescence.
Purpose of the Study:
- To investigate the effect of local structural symmetrization on the luminescence properties of various polytypes within K2XF6 crystals doped with Mn4+.
- To analyze how changes in local symmetry and Mn-F bond length influence energy levels and optical transitions.
Main Methods:
- Utilized first-principles methods, Discrete Variational Xα (DV-Xα) and Discrete Variational Multi Electron (DVME), to model seven-atom clusters.
- Calculated molecular orbital energies, multiplet energy levels, and Coulomb integrals for different K2XF6 crystal structures.
- Incorporated lattice relaxation, Configuration Dependent Correction (CDC), and Correlation Correction (CC) to accurately reproduce multiplet energies.
Main Results:
- Observed that decreasing Mn-F bond length increases the 4A2g→4T2g (4F) and 4A2g→4T1g (4F) energies, while decreasing the 2Eg → 4A2g energy.
- Found that lower symmetry leads to smaller Coulomb integrals, reducing electron-electron repulsion.
- Qualitatively reproduced multiplet energies of Mn4+ doped K2XF6 crystals.
Conclusions:
- Local structural symmetrization significantly influences the luminescence properties of Mn4+-doped K2XF6 red phosphors.
- Reduced electron-electron repulsion in lower symmetry environments is a key factor in the observed changes in R-line energy.
- This study provides foundational insights into tailoring phosphor performance through structural control.
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