Dr Emma Barney is an assistant professor in the department of Mechanical, Materials and Manufacturing Engineering at the University of Nottingham. Emma completed her PhD in Physics at the University of Warwick in 2008 and, upon completion, Emma was employed by STFC as an instrument scientist for the GeM diffractometer at the ISIS Pulsed Neutron and Muon Source, Rutherford Appleton Laboratory (2008-2011). Whilst working at ISIS, Emma developed a strong research programme, investigating complex heavy metal oxide glasses, while also forming collaborations to study bio-active glasses, metallic glasses, metal-organic frameworks and cyanides. In 2011 Emma was awarded the 2-year Nottingham Advanced Research (NAR) Fellowship at the University of Nottingham. The focus of this Fellowship was to apply her understanding of lone pair ions in glasses to technologically relevant arsenic based mid-infrared (mid-IR) optical glasses. Following the completion of the fellowship, Emma was awarded a lectureship. Emma is a fellow of the Society of Glass Technology, and is recorder for the board of Fellows which reviews membership and prizes. She is currently also on the council for the society and is an active member of the Basic Science and Technology Committee for that body.
Developing new potentials to model the structure of multicomponent glasses using diffraction data
Emelie Nilsson, 1 Teo Kubiena, 1 James Towey, 1 Uresha Patel,1 Ifty Ahmed,1 Alex Hannon,2 and Emma Barney*1
1Advanced Materials Research Group, Faculty of Engineering, University of Nottingham, Nottinghamshire, UK
2 ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire, UK
Diffraction data have been used to accurately determine the short range structure in a wide range of simple binary and ternary glasses. However, glasses with industrial applications tend to be far more complex, with multiple modifying oxides added to optimise properties. Reliably extracting structural information from these glasses, where there are multiple overlapping peaks in the correlation functions, is challenging and requires careful analysis. This study has utilised the Empirical Potential Structure Refinement software to reliably deconvolute the overlapping contributions to the correlation functions. To achieve this for a particular glass series, model the structural information for multiple compositions have been used to develop a single set of potentials that reproduce all the data. In this study, the structural analysis for a range of complex glasses will be presented including bioactive phosphate glasses, multi component silicate glasses, tellurite glasses and chalcogenides. This cross section of systems will highlight the strengths and weaknesses of the proposed techniques for glass systems exhibiting minimal changes in local environment with composition, changes in coordination numbers, and homopolar bonding.
Figure 1: EPSR fits to neutron diffraction data for four binary phosphate glasses
Figure 2: A comparison of the magnesium environment in binary and quaternary phosphate glasses.
Figure 3: The changes in tellurium coordination number extracted from EPSR for a series of Barium tellurite glasses.