相关论文: Pressure Raman effects and internal stress in netw…
We study an integer automaton elasto-plastic model of an amorphous solid subject to cyclic shear of amplitude $\Gamma$. We focus on the reversible plastic regime at intermediate $\Gamma_0<\Gamma<\Gamma_y$, where, after a transient, the…
Non-reversing relaxation enthalpies (DHnr) at glass transitions Tg(x) in the PxGexSe1-2x ternary display wide, sharp and deep global minima (~ 0) in the 0.09 < x < 0.145 range, within which Tgs become thermally reversing. In this…
In this paper we report a new high-pressure rhombohedral phase of Ce2Zr2O8 observed from high-pressure angle-dispersive x-ray diffraction and Raman spectroscopy studies up to nearly 12 GPa. The ambient-pressure cubic phase of Ce2Zr2O8…
Room-temperature Raman scattering has been measured in lead tungstate up to 17 GPa. We report the pressure dependence of all the Raman modes of the tetragonal scheelite phase (PbWO4-I, space group I41/a), which is stable at ambient…
We report high pressure Raman experiments of Black phosphorus up to 24 GPa. The line widths of first order Raman modes A$^1_g$, B$_{2g}$ and A$^2_g$ of the orthorhombic phase show a minimum at 1.1 GPa. Our first-principles density…
In this article, we estimate hydrostatic stress developed in gallium ion implanted gallium nitride epitaxial layers using Raman measurements. We have calculated deformation potential constants for $E_2$(high) mode in these epi-layers. The…
Near-bandgap Raman scattering was used to induce and study photostructural changes in AsxS100-x bulk glasses revealing a new photoinduced polymerization effect. Raman spectra were recorded also in off-resonant conditions allowing for a…
In the framework of topological constraint theory, network glasses are classified as flexible, stressed--rigid, or isostatic if the number of atomic constraints is smaller, larger, or equal to the number of atomic degrees of freedom. Here,…
BiTeI is a giant Rashba spin splitting system, in which a non-centro symmetric topological phase has recently been suggested to appear under high pressure. We investigated the optical properties of this compound, reflectivity and…
Electrostatic gating offers elegant ways to simultaneously strain and dope atomically thin membranes. Here, we report on a detailed \textit{in situ} Raman scattering study on graphene, suspended over a Si/SiO$_2$ substrate. In such a…
Raman spectroscopic studies have been carried out on CaCrO4 under pressure up to 26GPa at ambient temperature. The Raman spectra showed CaCrO4 experienced a continuous structural phase transition started at near 6GPa, and finished at about…
The effect of pressure on the crystalline structure and superconducting transition temperature (Tc) of the 111-type Na1-xFeAs system using in situ high pressure synchrotron x-ray powder diffraction and diamond anvil cell techniques is…
Simulations are used to examine the microscopic origins of strain hardening in polymer glasses. While stress-strain curves for a wide range of temperature can be fit to the functional form predicted by entropic network models, many other…
Strong changes in bulk properties, such as modulus and viscosity, are observed near the glass transition temperature, T_{g}, of amorphous materials. For more than a century, intense efforts have been made to define a microscopic origin for…
We report Raman spectra and synchrotron x-ray diffraction measurements of lattice parameters of polycrystalline MgB2 under hydrostatic pressure conditions up to 15 GPa. An anomalously broadened Raman band at 620 cm-1 is observed that…
Two dimensional ferroic materials exhibit a variety of functional properties that can be tuned by temperature and pressure. CuInP2S6 is a layered material that is ferrielectric at room temperature and whose properties are a result of the…
In a recent publication we established an analogy between the free energy of a hard sphere system and the energy of an elastic network [1]. This result enables one to study the free energy landscape of hard spheres, in particular to define…
We grow AlN/4H-SiC and AlN/6H-SiC heterostructures by physical vapor deposition and characterize the heterointerface with nanoscale resolution. Furthermore, we investigate the spatial stress and strain distribution in these heterostructures…
A dynamical phase transition from reversible to irreversible behavior occurs when particle suspensions are subjected to uniform oscillatory shear, even in the Stokes flow limit. We consider a more general situation with non-uniform strain…
The requirement that packings of hard particles, arguably the simplest structural glass, cannot be compressed by rearranging their network of contacts is shown to yield a new constraint on their microscopic structure. This constraint takes…