The mechanism behind SnO metallization under high pressure
Year: 2022
Authors: Pesach A., Nguyen L., Gorelli F.A., Bini R., Hevroni R., Nikolaevsky M., Dos Santos A.M., Tulk C.A., Molaison J.J., Shuker R., Melchior A., Caspi E.N., Salem R., Makov G., Sterer E.
Autors Affiliation: Nucl Res Ctr Negev, Dept Phys, POB 9001, IL-84109 Beer Sheva, Israel; European Lab Nonlinear Spect, LENS, Via N Carrara 1, I-50019 Florence, Italy; Univ Firenze, Dipartimento Chim Ugo Schiff, Via Lastruccia 3, I-50019 Florence, Italy; Oak Ridge Natl Lab, Neutron Scattering Div, Oak Ridge, TN 37830 USA; Ben Gurion Univ Negev, Dept Phys, POB 563, IL-84105 Beer Sheva, Israel; Ben Gurion Univ Negev, Dept Mat Engn, IL-84105 Beer Sheva, Israel.
Abstract: SnO is known to undergo metallization at similar to 5 GPa while retaining its tetragonal symmetry. However, the mechanism of this metallization remains speculative. We present a combined experimental and computational study including pressure-dependent infrared spectroscopy, resistivity, and neutron powder diffraction measurements. We show that, while the excess charge mobility increases with pressure, the lattice distortion, in terms of the z-position of Sn, is reduced. Both processes follow a similar trend that consists of two stages, a moderate increment up to similar to 3 GPa followed by a rapid increase at higher pressure. This behavior is discussed in terms of polaron delocalization. The pressure-induced delocalization is dictated by the electron-phonon coupling and related local anisotropic lattice distortion at the polaron site. We show that these polaronic states are stable at 0 GPa with a binding energy of similar to 0.35 eV. Upon increasing the pressure, the polaron binding energy is reduced with the electron-phonon coupling strength of Gamma and M modes, enabling the electrical phase transition to occur at similar to 3.8 GPa. Further compression increases the total electron-phonon coupling strength up to a maximum at 10 GPa, which is a strong evidence of dome-shaped superconductivity transition with T-c = 1.67 K.
Journal/Review: RESULTS IN PHYSICS
Volume: 39 Pages from: 105750-1 to: 105750-“10
More Information: G.M. acknowledges the support of the Israel Ministry of Science and Technology. E.S. acknowledge the support of the Pazy Foundation Grant 326-1/22. The IR measurements were taken at the LENS lab in Florence and sponsored by grant No. LENS 000373. A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory.KeyWords: High Pressure; Phase transition; Neutron diffraction; Polaron; metallizationDOI: 10.1016/j.rinp.2022.105750Citations: 1data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-10-20References taken from IsiWeb of Knowledge: (subscribers only)