TY  - JOUR
AU  - Friedrich, Alexandra
AU  - Winkler, Björn
AU  - Morgenroth, Wolfgang
AU  - Perlov, Alexander
AU  - Milman, Victor
TI  - Pressure-induced spin collapse of octahedrally coordinated Mn<sup>3+</sup> in the tetragonal hydrogarnet henritermierite Ca<sub>3</sub>Mn<sub>2</sub>[SiO<sub>4</sub>]<sub>2</sub>[O<sub>4</sub>H<sub>4</sub>]
JO  - Physical review / B
VL  - 92
IS  - 1
SN  - 1098-0121
CY  - College Park, Md.
PB  - APS
M1  - PUBDB-2015-05370
SP  - 014117
PY  - 2015
AB  - The high-pressure behavior of natural henritermierite garnet with close to end-member composition Ca<sub>3</sub>Mn<sub>2</sub>[SiO<sub>4</sub>]<sub>2</sub>[O<sub>4</sub>H<sub>4</sub>] 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<sup>3+</sup> and a pronounced reduction of the Jahn-Teller distortion of the Mn<sup>3+</sup>O<sub>4</sub>(OH)<sub>2</sub> octahedra. In the high-pressure phase the Jahn-Teller distortion is totally suppressed and the Mn<sup>3+</sup> 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
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000358841400001
DO  - DOI:10.1103/PhysRevB.92.014117
UR  - https://bib-pubdb1.desy.de/record/291398
ER  -