Nanocubic boron nitride/nanodiamond multilayer structures

Nanocubic boron nitride/nanodiamond (N -cBN/ND) multilayer structures with each alternating layer being ∼100 nm thick have been prepared by magnetron sputter and microwave plasma enhanced chemical vapor depositions. These multilayers exhibit remarkable properties, in particular, the mechanical properties. The multilayer structure is characteristic with (i) extreme hardness (82 GPa) considerably surpassing the values of the individual materials from which the multilayer is composed, (ii) high surface smoothness, (iii) significantly reduced film stress when compared with a single cBN layer of equivalent thickness, and (iv) great chemical stability. The N -cBN/ND multilayers developed have therefore important implications in mechanical and chemically resistant applications. © 2007 American Institute of Physics.