Neutron Diffraction with an Excess-Water Cell

Neutron diffraction studies of water and aqueous solutions under pressure

2014 A summary is given of data obtained from neutron diffraction experiments on heavy water at elevated pressures and temperatures using three different types of pressure vessel. The pressure vessels were manufactured from (i) hard steel (EN24T), (ii) titanium-zirconium null alloy, and (iii) autofrettaged aluminium alloy (7075-T6). In cases (i) and (ii), hydraulic pressures up to 6 kbar were a...

Neutron Diffraction Experiments

This ISEN award supported research toward improving the energy efficiency of actuators. The focused research objective was to develop next-generation shape memory alloy (SMA) models and structures, to demonstrate this new technology in targeted near-term applications on airplanes. Two research avenues were pursued to enable development of this new technology: 1) neutron diffraction experiments ...

Biological Neutron Diffraction

An Extremum Principle for a Neutron Diffraction Experiment

An extremum principle was postulated by Horne, Finkelstein, Shull, Zeilinger, and Bernstein in order to derive the physically allowable parameters for sinusoidal standing waves governing a neutron in a crystal which is immersed in a strong external magnetic field: `̀ the expectation value of the total potential á V ñ is an extremum .’’ We show that this extremum principle can be obtained from th...

Magnetic structure of greigite (Fe3S4) probed by neutron powder diffraction and polarized neutron diffraction

[1] We have investigated greigite (Fe3S4) using a combination of neutron powder diffraction and polarized neutron diffraction to give the first unambiguous assignment of its magnetic structure. Our results confirm that greigite has a collinear ferrimagnetic structure with antiferromagnetic coupling between the tetrahedral (A) and octahedral (B) sites. Our analysis also indicates that greigite d...