Effect of nanostructuration on compressibility of cubic BN

TL;DR

This study investigates how nanostructuring affects the compressibility of cubic boron nitride (cBN), revealing a slight decrease in bulk modulus due to nanometer grain sizes using high-pressure synchrotron X-ray diffraction.

Contribution

It provides the first detailed measurement of the bulk modulus of nanostructured cBN under high pressure, highlighting the impact of nanostructure on its mechanical properties.

Findings

Bulk modulus B0 = 375 GPa with B0' = 2.3.

Nanometer grain size reduces bulk modulus by approximately 9%.

High-pressure measurements up to 35 GPa using synchrotron X-ray diffraction.

Abstract

Compressibility of high-purity nanostructured cBN has been studied under quasi-hydrostatic conditions at 300 K up to 35 GPa using diamond anvil cell and angle-dispersive synchrotron X-ray powder diffraction. A data fit to the Vinet equation of state yields the values of the bulk modulus B0 of 375(4) GPa with its first pressure derivative B0' of 2.3(3). The nanometer grain size (\sim20 nm) results in decrease of the bulk modulus by ~9%.