Pressure-induced irreversible disorder in β'-Mn3(PO4)2: a high-pressure X-ray diffraction and density-functional
Ana Melissa P Brito1, Neha Bura2, Pablo Botella2
1LSQM-Laboratory of Chemical Synthesis of Materials-Department of Materials Engineering, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil.
Dalton Transactions (Cambridge, England : 2003)
|July 14, 2026
Summary
High-pressure studies reveal that manganese phosphate undergoes irreversible structural disorder above 14.1 GPa due to anisotropic compression and Mn-O polyhedra distortions. This transformation impacts complex phosphate frameworks.
Area of Science:
- Materials Science
- Solid-State Chemistry
- Geophysics
Background:
- Manganese phosphate (β'-Mn3(PO4)2) exhibits a monoclinic structure at ambient conditions.
- Understanding the high-pressure behavior of complex phosphate frameworks is crucial for materials science and geophysics.
Purpose of the Study:
- To investigate the high-pressure structural behavior and compressibility of β'-Mn3(PO4)2.
- To elucidate the mechanisms of pressure-induced structural disorder and its irreversibility.
Main Methods:
- Synchrotron X-ray diffraction up to 20 GPa.
- Density-functional theory (DFT) calculations.
- Third-order Birch-Murnaghan equation of state analysis.
Main Results:
- β'-Mn3(PO4)2 shows anisotropic compression, with Mn-O polyhedra distorting significantly while PO4 tetrahedra remain rigid.
- Irreversible structural disorder and loss of long-range order occur above 14.1 GPa, persisting after pressure release.
- DFT calculations accurately predicted experimental compressional behavior and revealed Mn-site coordination changes and elastic instabilities.
Conclusions:
- The high-pressure response is governed by framework complexity, anisotropic polyhedral compressibility, and elastic instability.
- Pressure-induced structural degradation in complex phosphate frameworks is a complex phenomenon.
- The study provides new insights into the mechanical properties and structural transformations of manganese phosphate under extreme conditions.
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