%0 Journal Article
%A Friedrich, Alexandra
%A Winkler, Björn
%A Morgenroth, Wolfgang
%A Perlov, Alexander
%A Milman, Victor
%T 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>]
%J Physical review / B
%V 92
%N 1
%@ 1098-0121
%C College Park, Md.
%I APS
%M PUBDB-2015-05370
%P 014117
%D 2015
%X 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
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000358841400001
%R 10.1103/PhysRevB.92.014117
%U https://bib-pubdb1.desy.de/record/291398