Quasi-2D Phonon Transport in Diamond Nano Thin Film

FIB Diamon Nano Thin Film with thickness of 60-100 nanometer can still  carry a thermal conductivity up to 2000/W/mk

Nanomaterial phonon transport is crucial for miniaturized devices and superior thermophysical properties in condensed matter physics.

Diamond nanosheets, applicable in nanoelectronics/optoelectronics, offer availability to explore dimensionality's impact on phonon transport. Raman spectroscopy is used to study the thermal conductivity (κ) of diamond nanosheets with a thickness below 100 nm. Results show a κ∼T−1 law above 140 K, highlighting Umklapp phonon scattering. 

Despite the reduced thickness, κ (1100-2000 W/mK) remains higher than metals and most semiconductors, showcasing diamonds' remarkable in-plane heat transfer. Intriguingly, the research uncovers unique length-dependent behavior κ∼log⁡(L), consistent with graphene, the two-dimensional (2D) allotrope.