RAMAN-SCATTERING FROM CUBIC BORON-NITRIDE UP TO 1600-K

Raman scattering measurements on cubic boron nitride up to 1600 K are reported. The results indicate that at 1600 K the interatomic force constant is only approximately 10% weaker than at room temperature and that cubic BN is therefore a good candidate for applications where high-temperature mechanical strength is required. However, contrary to the behavior found for diamond, where the frequency changes with temperature were very nonlinear, it is found that in boron nitride both the TO and LO shift linearly with temperature at a rate of -0.036 cm-1/K.