Testimonial: University of Sheffield
The crystallography facility here in Sheffield is based within the Chemistry Division of the School of Mathematics and Physical Sciences. The facility caters to a wide range of synthetic chemists and materials scientists, providing structural analysis for a variety of chemical compounds and materials within the School and the wider scientific community in Sheffield. The majority of the facility output involves structure determination and is provided as a service to research groups or conducted by postdoctoral and PhD student users, after suitable training. Advanced characterisation is performed by members of the materials chemistry research cluster within the Chemistry Division. Such work, performed by researchers in Prof Brammer’s group, includes using in situ diffraction techniques to understand structure-property relationships of a variety of molecular and polymeric materials (e.g. MOFs) which display dynamic responses to external stimuli.
What was the main problem, or challenge, that you were trying to solve by buying a new diffractometer system?
In recent years the reduction in crystallite size of samples being submitted to the service had resulted in an increasing number of challenging samples leading to a higher reliance on external facilities (such as the National Crystallography Service) or requiring very long acquisition times. The recent investment in the service was, therefore, an attempt to combat these challenges and to reduce reliance on external facilities. This investment also included retiring some older instrumentation in the lab. Initially, we had considered purchasing a dual-source sealed-tube system that would replace older instrumentation in the lab, improving acquisition time and facility capabilities in handling smaller crystals. Shortened acquisition times, we anticipated, would also result in improved opportunities for, often time-consuming, in situ studies within the materials chemistry cluster.
How has the new instrument from Rigaku Oxford Diffraction changed the workflow in your lab?
Ultimately, we opted for the Rigaku Synergy-R diffractometer with a rotating-anode Cu source, as we concluded it would offer some significant advantages over a microfocus sealed-tube source, albeit at the sacrifice of having a dual source instrument, as a dual-source rotating anode instrument exceeded our budget. The Rigaku Synergy-R system has substantially reduced data acquisition time for single-crystal X-ray diffraction with a consequent dramatic effect of the overall turnaround time of samples characterised in the Chemistry X-ray structure service. The ability to study much smaller crystals has also increased the facility output, with researchers being less reliant on recrystallisation protocols to obtain crystals of larger size to enable analysis. Overall, this has reduced our need for national facilities for structure determination, as we had envisioned. The motorised beam divergence slits have also allowed us to conduct PXRD studies conveniently on very small amounts of sample and with reasonable data quality, although we have a separate powder diffractometer, which is also used extensively.
Finally, the higher throughput has also led to friendly competition between other instrumentation facilities within the Chemistry Division, with the X-ray service facility in some cases providing turnaround times for characterisation competitive with some of the routine spectroscopic techniques.
Can you describe the single most important benefit the XtaLAB Synergy-R system brings to your research?
The ability to study smaller crystals has changed our perspective on what is achievable within our facility. Indeed, some samples that previously required study at synchrotron facilities can now be studied in-house. Although the acquisition times are longer than synchrotron studies, the time spent in-house is well spent and frees up time at those facilities to solve other challenges. The rapid turnaround time in-house for structure determination of “standard” samples has also made it easier to provide the extended instrument time needed for more challenging samples or in situ studies.
Which other features of the XtaLAB Synergy-R system are important to you?
As new users of a rotating-anode system, we encountered some challenges. In particular, understanding radiation damage, due to increased X-ray flux compared to sealed-tube instruments, has been vital to avoid sample degradation during data acquisition. The motorised divergence slits have proved to be an invaluable (easy-to-use) tool for beam attenuation. This feature has also been routinely deployed to reduce spot size and overlap when looking at twinned crystals and is very useful when collecting powder diffraction patterns on the Synergy-R system. The ability to record reasonable powder diffraction data on minute sample quantities has allowed the X-ray facility to expand its user base and accommodate more materials scientists, especially in cases where researchers require use of an area detector for PXRD. The shorter acquisition times, when coupled with the XtalCheck-S plate reader, have also presented a valuable opportunity to develop a multi-crystal approach, which we had been previously exploring at central facilities. The addition of the XtalCheck-S device has further increased the prospective user base to include research within the School of Bioscience and biochemists within the school.
What would you say to anyone considering making a purchase of a new high capability diffractometer? Would you recommend the XtaLAB Synergy-R system?
Prior to the purchase of the Synergy-R instrument, our facility had solely operated only sealed-tube instruments. There was some hesitancy in considering purchase of a rotating-anode system, including perceived higher operational/maintenance costs and concerns with reliability and stability of such sources. Within our available budget, it also meant sacrificing the option of having a dual-source Cu/Mo instrument. We spoke to a number of other users about their experiences (positive or negative) with the Synergy rotating-anode instruments, which of course everyone should do as part of their evaluation process in making a major purchase. We made a number of experimental measurements to compare the Synergy-R with sealed-tube diffractometer options and concluded that the higher flux, and associated decrease in data acquisition time or decrease in accessible crystal size, combined with a variety of ancillary features that offered us new research opportunities made the Synergy-R the best choice for us at the time of purchase (2024).
We have had the diffractometer in operation for a little over one year at the time of writing. There have been some minor problems, but nothing that could not be solved fairly quickly. The instrument has been reliable. Cathode changes (3 times per year) are straightforward to conduct ourselves. Anode changes (annually) require Rigaku engineers to conduct and can be covered within an annual maintenance contract. Our first anode change went smoothly and resulted in no substantial change in X-ray intensity. We have had to make some adjustments in workflow, but the benefits clearly outweigh the adjustments needed.
Is there anything else that you would like to add about your experience of working with Rigaku Oxford Diffraction?
The user support team at Rigaku have resolved instrument issues in a timely manner and the training and support we have received from the applications team has been generous and of a high standard. CrysAlisPro is a highly customisable software package with a comprehensive user support system. The written support is extensive with, in part, a suitable level of comedic commentary (e.g. gral help).