A novel, pixellated, energy-resolving X-ray detector has been utilised to simultaneously combine angular and energy dispersive X-ray diffraction (XRD). This approach allows a system to measure XRD data using the benefits of both approaches. Data acquisition is fast, and the system contains no moving parts, making it ideal for applications in security, particularly for the detection of explosive materials hidden within packages or baggage. Explosive samples supplied by the Centre for Applied Science and Technology, U.K. were examined using the pixellated diffraction technique, and the XRD data were compared with those from inert materials typically found inside luggage. A method of processing the data was developed, which greatly reduces the amount of data outputted from the detector whilst preserving the angular and energy resolution. Using principal component and discriminant analyses, a model was developed which predicts the correct classification of an unknown sample as either "explosive" or "inert" for data with acquisition times as low as one second.

We have successfully induced multiferroic behavior in the A-type antiferromagnet SmMnO3 by the substitution of Y at the Sm site. A magnetic transition develops at ∼ 24 K for Sm1−xYxMnO3 (x = 0.4, 0.5) which is not present in the parent compound. This transition coincides with the onset of electric order, with an electric polarization measured along the c axis. It is proposed that the eÿect of Y doping is to bring about a subtle distortion of the MnO6 octahedra, causing a magnetic ordering of the Mn 3+ moments similar to that reported for the well studied multiferroic TbMnO3. Following on from our previous study on polycrystalline samples, we present measurements of the magnetic and electric properties of single crystal Sm0.6Y0.4MnO3 and Sm0.5Y0.5MnO3. The data are summarized in a phase diagram for each of the principal crystallographic axes for the x = 0.5 compound. Powder neutron diÿraction experiments on SmMnO3 and Sm0.6Y0.4MnO3 show that the Y substitution causes a change in the Mn-O-Mn bond angle towards the value found for TbMnO3. The magnetic structure of Sm0.6Y0.4MnO3 has been shown to consist of two phases: a sinusoidal ordering of the Mn 3+ moments below 50 K and a cycloidal ordering below 27 K. The cycloidal ordering occurs at the same temperature as the previously observed ferroelectric polarization, suggesting a similar multiferroic mechanism to that found in TbMnO3.

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