Influence of strain on thermal conductivity of ScF3 crystal

What is it about?

All materials are known to have an important physical property known as “lattice thermal conductivity.” This gives them the ability to conduct heat. This ability to conduct heat can increase or decrease under the impact of deforming forces, called “strain.” Some materials are known to behave unconventionally in this regard. Previous studies suggest this may be due to a property known as “negative thermal expansion,” (NTE). But, a detailed study of the relation between thermal expansion and a material's heat conduction ability is lacking. In this study, the authors looked at an NTE material, scandium fluoride (ScF3), to understand this link better. To do this, they used a method called “first principles calculations.” They looked at how heat transfer changed under compression and stretching. They found that the heat conduction in ScF3 showed an anomalous dependence on strain. This anomaly resulted from the innate nature of the NTE parameter.

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Photo by Anne Nygård on Unsplash

Photo by Anne Nygård on Unsplash

Why is it important?

All materials change in size with temperature. Such changes are important in many fields. For example, the size of tiny mechanical systems and optical elements needs to be accurate for them to work properly. But, temperature changes can make this challenging since the materials undergo thermal expansion. One way to solve such problems is by using NTE materials like ScF3. While ScF3 shrinks with rising temperature, this shrinkage can be tuned by compressing or stretching the crystal. The results of this study can help us develop other materials with unique thermal properties. In turn, this can boost the performance of devices used in microscopy, electronics, sensors, robotics, and more. KEY TAKEAWAY: This study sheds light on the unique thermal properties of ScF3. This can pave the way for new and improved technologies.