guest ::
| Home > Publications database > Pressure-induced spin collapse of octahedrally coordinated $\mathrm{Mn^{3+}}$ in the tetragonal hydrogarnet henritermierite $\mathrm{Ca_{3}Mn_{2}[SiO_{4}]_{2}[O_{4}H_{4}]}$ |
| Home > Publications database > Pressure-induced spin collapse of octahedrally coordinated $\mathrm{Mn^{3+}}$ in the tetragonal hydrogarnet henritermierite $\mathrm{Ca_{3}Mn_{2}[SiO_{4}]_{2}[O_{4}H_{4}]}$ |
| Journal Article | PUBDB-2015-05370 |
; ; ; ;
2015
APS
College Park, Md.
This record in other databases: 
Please use a persistent id in citations: doi:10.1103/PhysRevB.92.014117
Abstract: The high-pressure behavior of natural henritermierite garnet with close to end-member composition Ca$_{3}$Mn$_{2}$[SiO$_{4}$]$_{2}$[O$_{4}$H$_{4}$] was studied at pressures up to 80 GPa using single-crystal synchrotron x-ray diffraction, Raman spectroscopy, and quantum-mechanical calculations based on density functional theory. An isosymmetric phase transition was observed in the pressure range between 55 and 70 GPa, which is associated with a gradual high-spin to low-spin electronic transition in Mn$^{3+}$ and a pronounced reduction of the Jahn-Teller distortion of the Mn$^{3+}$O$_{4}$(OH)$_{2}$ octahedra. In the high-pressure phase the Jahn-Teller distortion is totally suppressed and the Mn$^{3+}$ is in a low-spin configuration. Experimental structural data before and after the phase transition are in excellent agreement with the theoretically predicted structural compression of the high-spin and low-spin phases, respectively. While the overall unit-cell volume is reduced by about 1.5% across the phase transition, a collapse of about 4–5% of the MnO6 octahedral volume is observed. The high-spin phase shows a bulk modulus B = 101(1) GPa and its pressure derivative B'= 4.5(1). The bulk moduli of the coordination polyhedra are B$_{MnO6}$ = 178(2) GPa, B$_{Ca1O8}$ = 101.2(5) GPa, B$_{Ca2O8}$ = 88.4(8) GPa, B$_{SiO4}$= 337(5) GPa, and B$_{O4H4}$ = 29(1) GPa for the high-spin phase. Mode Gr¨uneisen parameters range between 0.34 and 0.94. The computed spin-pairing energy is ≈3.6 eV at 0 GPa.
; 
; 
; Current Contents - Physical, Chemical and Earth Sciences ; IF < 5 ; JCR ; Nationallizenz
; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection
|
The record appears in these collections: |
PDF
PDF (PDFA)