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Updated: Oct 18, 2025

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Low-frequency vibrational spectroscopy: a new tool for revealing crystalline magnetic structures in iron phosphate
Zihui Song1, Xudong Liu2, Anish Ochani3
1Department of Chemistry, 82 University Place, University of Vermont, Burlington, VT, 05405, USA. michael.ruggiero@uvm.edu.
Abstract:
In this report, the strong-dependence of low-frequency (terahertz) vibrational dynamics on weak and long-range forces in crystals is leveraged to determine the bulk magnetic configuration of iron phosphate - a promising material for cathodes in lithium ion batteries. We demonstrate that terahertz time-domain spectroscopy - coupled with quantum mechanical simulations - can discern between various spin configurations in FePO4. Furthermore, the results of this work unambiguously show that the well-accepted space group symmetry for FePO4 is incorrect, and the low-frequency spectroscopic measurements provide a clearer picture of the correct structure over the gold-standard of X-ray diffraction. This work opens the door for characterizing, predicting, and interpreting crystalline magnetic ordering using low-frequency vibrational spectroscopy.
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