TY - JOUR

T1 - Raman Spectroscopy of Tin Monoxide under High Pressure

AU - Shuker, Reuben

AU - Pesach, Asaf

AU - Raman Laboratory Team, null

PY - 2013/6/1

Y1 - 2013/6/1

N2 - Under ambient conditions, tin monoxide crystallizes in litharge
structure which consists of tetragonal P4/nmm symmetry. An orthorhombic
distortion of this compound at high pressure is assumed to be driven by
softening of the unobserved B1 g phonon, which results in a
spontaneous strain in the xy plane of the tetragonal unit cell. In this
case, a reduction of the symmetry into Pm21 n occurs. The
correlation between the tetragonal and orthorhombic symmetries shows a
splitting of the degenerated Eg phonon into a superposition
of A1 and B1 phonons in the lower symmetry. This
splitting was observed in our pressure dependent Raman scattering
measurements. The changes in the pressure induced Raman spectrum of tin
monoxide can be quantitatively obtained by first order perturbation
theory. The frequency of this phonon under stress is obtained by
diagonalizing the relevant matrix. This procedure gives a frequency
shift and splitting of Eg phonon as a function of pressure
induced strain. By means of Landau's classical free energy theory this
order parameter gives a critical pressure value of 1.03 GPa for the
phase transition.

AB - Under ambient conditions, tin monoxide crystallizes in litharge
structure which consists of tetragonal P4/nmm symmetry. An orthorhombic
distortion of this compound at high pressure is assumed to be driven by
softening of the unobserved B1 g phonon, which results in a
spontaneous strain in the xy plane of the tetragonal unit cell. In this
case, a reduction of the symmetry into Pm21 n occurs. The
correlation between the tetragonal and orthorhombic symmetries shows a
splitting of the degenerated Eg phonon into a superposition
of A1 and B1 phonons in the lower symmetry. This
splitting was observed in our pressure dependent Raman scattering
measurements. The changes in the pressure induced Raman spectrum of tin
monoxide can be quantitatively obtained by first order perturbation
theory. The frequency of this phonon under stress is obtained by
diagonalizing the relevant matrix. This procedure gives a frequency
shift and splitting of Eg phonon as a function of pressure
induced strain. By means of Landau's classical free energy theory this
order parameter gives a critical pressure value of 1.03 GPa for the
phase transition.

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JO - Topical Conference on the Shock Compression of Matter 2013

JF - Topical Conference on the Shock Compression of Matter 2013

ER -