44 research outputs found
Cobaltocene adsorption and dissociation on Cu(1 1 1)
Photoemission results indicate that the initial adsorption of cobaltocene on Cu(1 1 1) at 150 K leads to molecular fragmentation, but with subsequent cobaltocene exposures, molecular absorption occurs. The molecularly adsorbed species is either adsorbed with only a fraction of molecules adopting a preferential orientation along the surface normal or adsorbed with the molecular axis away from the surface normal. This adsorption behavior is compared to nickelocene and ferrocene adsorption
The survival of holes as thru-holes in thru-hole epitaxy: How can holes in 2D layers not sealed off during multiple stacking of those layers?
Thru-hole epitaxy was recently reported to be able to grow readily detachable
domains crystallographically aligned with the underlying substrate over 2D mask
material transferred onto a substrate. While the experimental demonstration of
thru-hole epitaxy of GaN over multiple stacks of -BN was evident, the
detailed mechanism of how small holes in each stack of -BN survived as
thru-holes during multiple stacking of -BN was not intuitively clear. Here,
we show through Monte Carlo simulations that in what conditions holes in each
stack of 2D mask layers can survive as thru-holes during multiple stacking. If
more holes are laterally connected, the survival rate of thru-holes increases
resulting in the epitaxial connectedness. This computational work verifies and
supports that thru-hole epitaxy is attributed to the epitaxial connectedness
established by thru-holes survived even through multiple stacks.Comment: 14 pages, 6 figure
Can photoemission accurately probe the bulk electronic structure of the complex oxides?
Influence of dynamical scattering in crystalline poly„vinylidene
The effective Debye temperature of poly(vinylidene fluoride-trifluoroethylene) copolymers was measured using photoemission and neutron diffraction techniques. An effective Debye temperature of 53611K is obtained from the photoemission data and 6963.5K from neutron diffraction measurements. This effective Debye temperature is a consequence of the temperature-dependent dynamic motions perpendicular to the surface of these crystalline polymer films
Influence of dynamical scattering in crystalline poly„vinylidene
The effective Debye temperature of poly(vinylidene fluoride-trifluoroethylene) copolymers was measured using photoemission and neutron diffraction techniques. An effective Debye temperature of 53611K is obtained from the photoemission data and 6963.5K from neutron diffraction measurements. This effective Debye temperature is a consequence of the temperature-dependent dynamic motions perpendicular to the surface of these crystalline polymer films
Lattice-Stiffening Transition in Copolymer Films of Vinylidene Fluoride (70%) with Trifluoroethylene (30%)
We report the discovery of a compressibility phase transition at 160 K in crystalline copolymer films of vinylidene fluoride ( 70%) with trifluoroethylene ( 30%). This phase transition is distinct from the known bulk ferroelectric-paraelectric phase transition at 353 K and surface ferroelectric phase transition at 295 K. The new phase transition is characterized by an increase in the effective Debye temperature from 48 to 245 K along the 〈010〉 direction as the temperature falls below 160 K. This phase transition is evident in neutron scattering, x-ray diffraction, angle-resolved photoemission, and in the dipole active phonon modes in electron energy-loss spectroscopy
Lattice-stiffening transition in copolymer films of vinylidene fluoride (70%) with trifluoroethylene (30%)
We report the discovery of a compressibility phase transition at 160 K in crystalline copolymer films of vinylidene fluoride (70%) with trifluoroethylene (30%). This phase transition is distinct from the known bulk ferroelectric-paraelectric phase transition at 353 K and surface ferroelectric phase transition at 295 K. The new phase transition is characterized by an increase in the effective Debye temperature from 48 to 245 K along the 〈010〉 direction as the temperature falls below 160 K. This phase transition is evident in neutron scattering, x-ray diffraction, angle-resolved photoemission, and in the dipole active phonon modes in electron energy-loss spectroscopy. © 1999 The American Physical Society