High-pressure electronic structure and phase transitions in monoclinic InSe: X-ray diffraction, Raman spectroscopy, and density functional theory

Abstract

International audienceWe have studied the crystal and electronic structure of monoclini

Experimental and Theoretical Studies on α-In2Se3 at High Pressure

“…39 The gradual transformation of β ′ phase into β phase and the fact that there is no volume discontinuity suggests that the β´→ β phase transition is a second-order transformation, 64 as the one observed under compression in the related compound InSe. 65 We will show below that these conclusions are supported by our HP-RS measurements and ab initio calculations. Note that a extrapolation of the α phase up to 1.2 GPa would yield a ∆V/V = 4% which is in good agreement with Ref.…”

Vibrational spectrum renormalization by enforced coupling across the van der Waals gap betweenMoS2andWS2Fan1, Zhu2, Ke3 et al. 2015Phys. Rev. B321221View full textAdd to dashboardCite

“…This can be attributed to a residual effect of the different degrees of Raman activity of the A 1g and B 1u modes in homo-bilayers. We also note that a similar mode repulsion has been observed in bulk InSe crystals under hydrostatic pressures below ~ 15GPa 26,27 . However, we also note the difference: in our work we probe vibration in membranes of truly atomic thicknesses, and the repulsion in our work is between two identical modes, which is possible in our experiments because they are from MoS 2 and WS 2 , respectively, and are thus spectrally distinguishable.…”

Pressure Impact on the Stability and Distortion of the Crystal Structure of CeScO3

“…A similar reduction of the lattice distortion has been observed in other materials like InSe; which transforms from monoclinic to tetragonal under HP, going through a second-order transition. 45 An extension of the pressure limits of this study will be needed to search for the existence of a pressure-driven phase transition in CeScO3 and to elucidate if such transition will be a second-order orthorhombic-tetragonal transition or a first-order one. 11 The anisotropy in the axial compressibility of CeScO3 (βa : βb : βc = 1.23 : 1.38 :…”