Thanks to the ISIS Pressure & Furnace, Electronics and Cryogenics groups, Oliver was able to measure the structure of the material B2O3 at temperatures all the way from 14 K to 1500 K, through its amorphous solid and liquid phases on the SANDALS instrument at ISIS.
In his study, published in The Journal of Chemical Physics, he combined these neutron results with previous results measured using synchrotron X-ray diffraction to produce X-ray–neutron difference functions. This is the first time this combination into a single analysis has been done for B2O3, for the glassy or liquid state.
Because neutrons see 11B more strongly in the presence of oxygen than X-rays, the contrast between the two was able to provide Oliver with new information about the structure. He was able to support the idea of the formation of boroxol ring structures in the glassy state, and their gradual dissolution at higher temperatures. The analysis could even resolve the subtle thermal expansion of the B–O bond.
“This work highlights the incredible sub-picometre precision to which we can measure distances between atoms, not just in crystals but also in liquids and glasses," says Oliver. “We can even accurately extract bond-length thermal expansion coefficients, which are important not only for understanding bulk expansion, but also for accurately interpreting structural changes in borates and other materials, which contribute to heat capacities and viscous flow mechanisms, among other important properties."
“I aim to build on this by exploiting the results to gain detailed understanding of the temperature-dependent structure in more complex glass melts, including borosilicates, boroaluminates, borogallates and borogermanates," he explains, adding; “these are important materials for a plethora of applications from high-temperature seals to optics."
To progress the research, Oliver is currently recruiting a PhD student, co-supervised by Dr Emma Barney at the University of Nottingham. The job vacancy provides more information for those who are interested.
The full paper can be found at DOI: 10.1063/5.0248235
