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Languages and Learning at Key Stage 2: A Longitudinal Study Final Report
In 2006, The Open University, the University of Southampton and Canterbury Christ Church University were commissioned by the then Department for Education and Skills (DfES), now Department for Children, Schools and Families (DCSF) to conduct a three-year longitudinal study of languages learning at Key Stage 2 (KS2). The qualitative study was designed to explore provision, practice and developments over three school years between 2006/07 and 2008/09 in a sample of primary schools and explore children’s achievement in oracy and literacy, as well as the possible broader cross-curricular impact of languages learning
Are the renormalized band widths in TTF-TCNQ of structural or electronic origin? - An angular dependent NEXAFS study
We have performed angle-dependent near-edge x-ray absorption fine structure
measurements in the Auger electron yield mode on the correlated
quasi-one-dimensional organic conductor TTF-TCNQ in order to determine the
orientation of the molecules in the topmost surface layer. We find that the
tilt angles of the molecules with respect to the one-dimensional axis are
essentially the same as in the bulk. Thus we can rule out surface relaxation as
the origin of the renormalized band widths which were inferred from the
analysis of photoemission data within the one-dimensional Hubbard model.
Thereby recent theoretical results are corroborated which invoke long-range
Coulomb repulsion as alternative explanation to understand the spectral
dispersions of TTF-TCNQ quantitatively within an extended Hubbard model.Comment: 6 pages, 5 figure
Re-entrant spin glass and magnetoresistance in Co_{0.2}Zn_{0.8}Fe_{1.6}Ti_{0.4}O_4 spinel oxide
We have investigated the static and dynamic response of magnetic clusters in
Co_{0.2}Zn_{0.8}Fe_{1.6}Ti_{0.4}O_4 spinel oxide, where a sequence of magnetic
phase transitions, i.e., paramagnetic (PM) to ferromagnetic at T_{C}
270K and ferromagnetic to canted spin glass state at T_f\leq$ 125K is
observed
One-Electron Singular Branch Lines of the Hubbard Chain
The momentum and energy dependence of the weight distribution in the vicinity
of the one-electron spectral-function singular branch lines of the 1D Hubbard
model is studied for all values of the electronic density and on-site repulsion
. To achieve this goal we use the recently introduced pseudofermion
dynamical theory. Our predictions agree quantitatively for the whole momentum
and energy bandwidth with the peak dispersions observed by angle-resolved
photoelectron spectroscopy in the quasi-1D organic conductor TTF-TCNQ.Comment: Replaced with shortened version; 4 figure
Profiling the interface electron gas of LaAlO3/SrTiO3 heterostructures by hard X-ray photoelectron spectroscopy
The conducting interface of LaAlO/SrTiO heterostructures has been
studied by hard X-ray photoelectron spectroscopy. From the Ti~2 signal and
its angle-dependence we derive that the thickness of the electron gas is much
smaller than the probing depth of 4 nm and that the carrier densities vary with
increasing number of LaAlO overlayers. Our results point to an electronic
reconstruction in the LaAlO overlayer as the driving mechanism for the
conducting interface and corroborate the recent interpretation of the
superconducting ground state as being of the Berezinskii-Kosterlitz-Thouless
type.Comment: 4 pages, 4 figure
Muon-spin relaxation measurements on the dimerized spin-1/2 chains NaTiSi2O6 and TiOCl
We report muon spin relaxation (muSR) and magnetic susceptibility
investigations of two Ti3+ chain compounds which each exhibit a spin gap at low
temperature, NaTiSi2O6 and TiOCl. From these we conclude that the spin gap in
NaTiSi2O6 is temperature independent, with a value of 2*Delta=660(50)K, arising
from orbital ordering at Too = 210K; the associated structural fluctuations
activate the muon spin relaxation rate up to temperatures above 270K. In TiOCl
we find thermally activated spin fluctuations corresponding to a spin gap
2*Delta=420(40)K below Tc1=67K. We also compare the methods used to extract the
spin gap and the concentration of free spins within the samples from muSR and
magnetic susceptibility data.Comment: 4 pages, 3 figure
Microscopic origin of the mobility enhancement at a spinel/perovskite oxide heterointerface revealed by photoemission spectroscopy
The spinel/perovskite heterointerface -AlO/SrTiO hosts a
two-dimensional electron system (2DES) with electron mobilities exceeding those
in its all-perovskite counterpart LaAlO/SrTiO by more than an order of
magnitude despite the abundance of oxygen vacancies which act as electron
donors as well as scattering sites. By means of resonant soft x-ray
photoemission spectroscopy and \textit{ab initio} calculations we reveal the
presence of a sharply localized type of oxygen vacancies at the very interface
due to the local breaking of the perovskite symmetry. We explain the
extraordinarily high mobilities by reduced scattering resulting from the
preferential formation of interfacial oxygen vacancies and spatial separation
of the resulting 2DES in deeper SrTiO layers. Our findings comply with
transport studies and pave the way towards defect engineering at interfaces of
oxides with different crystal structures.Comment: Accepted as Rapid Communications in Physical Review
Analysis of genetic and environmental sources of variation in serum cholesterol in Tecumseh, Michigan. V. Variance components estimated from pedigrees
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65164/1/j.1469-1809.1979.tb00668.x.pd
Electronic structure of the quasi-one-dimensional organic conductor TTF-TCNQ
We study the electronic structure of the quasi-one-dimensional organic
conductor TTF-TCNQ by means of density-functional band theory, Hubbard model
calculations, and angle-resolved photoelectron spectroscopy (ARPES). The
experimental spectra reveal significant quantitative and qualitative
discrepancies to band theory. We demonstrate that the dispersive behavior as
well as the temperature-dependence of the spectra can be consistently explained
by the finite-energy physics of the one-dimensional Hubbard model at metallic
doping. The model description can even be made quantitative, if one accounts
for an enhanced hopping integral at the surface, most likely caused by a
relaxation of the topmost molecular layer. Within this interpretation the ARPES
data provide spectroscopic evidence for the existence of spin-charge separation
on an energy scale of the conduction band width. The failure of the
one-dimensional Hubbard model for the {\it low-energy} spectral behavior is
attributed to interchain coupling and the additional effect of electron-phonon
interaction.Comment: 18 pages, 9 figure
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