Strengthening effects of interstitial nitrogen on rhenium

Introducing interstitial nitrogen atoms into the rhenium lattices is accepted for enhancing the mechanical and thermal properties of the metal. Here, we present an experimental study on the strengthening effects of interstitial nitrogen in rhenium on bulk modulus B₀ and elastic shear constant C₄₄ by comparing the difference in the compression and vibration behaviors between Re₃N and Re in the in situ high pressure angle dispersive X-ray diffraction and high-pressure Raman scattering. The incorporation of interstitial N atoms introduces the covalent bonding and the special Z-type structure along the c-axis, which caused the bulk modulus B₀ and elastic shear constant C₄₄ increase by 14% and 15%, and the incompressibility of the c-axis is obviously enhanced. In addition, this work well explains the strengthening effects of interstitial N atoms on mechanical and vibrational properties.