Bulk Hexagonal Boron Nitride with a Quasi-Isotropic Thermal Conductivity

Nanosheets dissipate heat in all directions

29 November 2018

A material that may prevent overheating in microscale electronics without causing short circuits has been created from graphene-like sheets.

Boron nitride nanosheets have been considered as heat sinks for computer chips because they can quickly dissipate heat, without conducting electricity. However, their desirable thermal conductivity occurs only in the plane of the nanosheets, not perpendicular to it.

Now, researchers from Deakin University have synthesized boron nitride pellets that exhibit high thermal conductivity in every direction. They compressed boron nitride nanosheets in a 2,000°C furnace while applying strong electrical pulses. X-ray and microscopy observations showed that this process caused the nanosheets to enlarge and pack into grains with random configurations.

Heat-dissipation measurements revealed that the chaotic grain structure of the pellets could rapidly reduce the temperature of a 100°C hot spot, no matter which way the material was facing.

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References

1. Advanced Functional Materials 28, 1707556 (2018). doi: 10.1002/adfm.201707556