Neutron Reflectometry Achieves Atomic-Scale Insights at 1,100°C, Study Shows: A New World Record?

For the first time, neutron reflectometry tests were conducted by ANSTO and UTS researchers above 1,100 degrees Celsius, setting a world record.

This new method combines the Spatz reflectometer with a vacuum oven to give atomic-level information about how thin films grow and spread, which could change thin film technology and devices.

Neutron Reflectometry Achieves Atomic-Scale Insights at 1,100°C, Study Shows — Getty Images/ Ian Waldie

Finding Out How Thin Films Move at High Temperatures

Francesca Iacopi and Aiswarya Pradeepkumar are in charge of the UTS team studying how graphene forms on SiC/Si surfaces when heated to very high temperatures. Their award-winning technology makes highly conductive devices that work with silicon production. Researchers used the strong Spatz neutron reflectometer at the Australian Centre for Neutron Scattering to examine how carbon grows and at what temperatures it starts to grow.

In real life, neutron reflectometry in complex sample setups can be used to study thin films from 1 to 100 nm. Adding a high-temperature vacuum heater lets you watch the film change in real time for minutes to hours. This step determines how well thin film technologies work since they can handle different processing and heat treatment circumstances.

The ANSTO-UTS partnership was led by Dr. Pradeepkumar, a research fellow at the ARC Centre for Transformative Meta-Optical Systems who received an AINSE Early Career Grant. The first experiment done in Australia on alloy-mediated epitaxial graphene production on 3C-SiC/Si surfaces gives us the information we haven't had before.

Record-breaking actions and future implications

A study in RSC Advances and Neutron News discussed the special qualities of high-temperature neutron reflectometry. Dr. Pradeepkumar says it has helped them learn more about alloy-mediated epitaxial graphene production on 3C-SiC/Si substrates, which has opened up new ways to improve 2D materials in nanoelectronics and nanophotonics.

For the high-temperature study, Dr. David Cortie and Dr. Anton Le Brun of ANSTO assembled the vacuum furnace and Spatz. The Neutron Scattering Sample Environment and Scientific Operations team made holders for the samples used in the studies, which made the process easier.

Le Brun said that this study is the first to record neutron reflectometry at the highest temperature. This feature is only occasionally found on a global scale. This work builds on Holt and his colleagues' groundbreaking work at the ISIS Pulsed.

Dr. Cortie said Spatz, which moved from HZB Berlin to the Australian Centre for Neutron Scattering in 2020, was a Neutron Source in England in the late 1990s. Flexible base for research at high temperatures. He said this would make it possible to use neutron reflectometry to study several crucial thin film processes, giving nanoscale information that many other probes can't access for the first time.

Epitaxial graphene on cubic silicon carbide on silicon surfaces could be used to make graphene-based electronics and photonics that can be scaled up. The 3C-SiC base has some problems, but a Ni/Cu catalyst has made it possible to cover it with graphene. This discovery lets us use operando analysis to find the best catalyst mixture and make more graphene.

Overall, ANSTO and UTS's high-temperature neutron reflectometry study breaks new ground by providing new information on the behavior of thin films. This helps to advance nanoelectronic and nanophotonic technologies. Adding high-temperature capabilities to current neutron reflectometry techniques is a big step forward in materials research. It could lead to better performance and new uses for thin film technology.