Extent of stacking disorder in diamond

Hexagonal diamond has been predicted computationally to display extraordinary physical properties including a hardness that exceeds cubic diamond. However, a recent electron microscopy study has shown that so-called hexagonal diamond samples are in fact not discrete materials but faulted and twinned cubic diamond. We now provide a quantitative analysis of cubic and hexagonal stacking in diamond samples by analysing X-ray diffraction data with the DIFFaX software package. The highest fractions of hexagonal stacking we find in materials which were previously referred to as hexagonal diamond are below 60%. The remainder of the stacking sequences are cubic. We show that the cubic and hexagonal sequences are interlaced in a complex way and that naturally occurring Lonsdaleite is not a simple phase mixture of cubic and hexagonal diamond. Instead, it is structurally best described as stacking disordered diamond. The future experimental challenge will be to prepare diamond samples beyond 60% hexagonality and towards the so far elusive 'perfect' hexagonal diamond

Poverty and inequality in Britain: 2005

This Commentary provides an update on trends in poverty and inequality in Great Britain, based on the latest official government statistics. It uses the same approach to measuring incomes and poverty in Great Britain as the government employs in its Households Below Average Income (HBAI) publication

Living standards, inequality and poverty

In this Election Briefing Note, we assess what has happened to living standards under Labour, setting out how average incomes, income inequality and poverty have changed since 1996- 97. We compare these changes with what happened under previous governments, and highlight where there have been differences between Labour's first and second terms

The William J. Haggerty collection of French colonial history

The Haggerty Collection consists of over 30,000 monographs, periodicals, reports, government publications, scrapbooks and ephemera from or pertaining to French colonies during the nineteenth and early twentieth centuries. The materials were originally part of the Union Coloniale Française, a private learning center established by French trading firms in 1894, renamed the Comité Central Français pour l’Outre-Mer in 1948. The collection was acquired by the State University of New York at New Paltz (and named for its president) in 1966 after the Comité was disbanded, coming to Binghamton University in 1984. While most of the Haggerty Collection is in French, other languages are represented and other European nations’ colonies are covered

Hydrogen mean force and anharmonicity in polycrystalline and amorphous ice

The hydrogen mean force from experimental neutron Compton profiles is derived using deep inelastic neutron scattering on amorphous and polycrystalline ice. The formalism of mean force is extended to probe its sensitivity to anharmonicity in the hydrogen-nucleus effective potential. The shape of the mean force for amorphous and polycrystalline ice is primarily determined by the anisotropy of the underlying quasi-harmonic effective potential. The data from amorphous ice show an additional curvature reflecting the more pronounced anharmonicity of the effective potential with respect to that of ice Ih.Comment: 12 pages, 7 figures, original researc