Temperature dependence of the cubic boron nitride Raman lines

Abstract

The first-order Raman spectra of single-crystal cubic boron nitride for the range of 300 to 1830 K are presented. The Stokes and anti-Stokes components of both the TO (\ensuremath{\Gamma}) and the LO (\ensuremath{\Gamma}) modes are analyzed for their Raman shift and width variation with temperature. The cubic boron nitride converted to hexagonal form in vacuo at 1840 K. The first-order Raman shifts up to this temperature, in units of ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$, can be written as \ensuremath{\nu}\ifmmode\bar\else\textasciimacron\fi{}=${\mathit{a}}_{0}$+${\mathit{a}}_{1}$T+${\mathit{a}}_{2}$${\mathit{T}}^{2}$ with coefficients 1060.6 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$, -0.010 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ ${\mathrm{K}}^{\mathrm{\ensuremath{-}}1}$, and -1.42\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}5}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ ${\mathrm{K}}^{\mathrm{\ensuremath{-}}2}$, respectively, for the TO (\ensuremath{\Gamma}) mode, and 1307.6 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$, -0.003 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ ${\mathrm{K}}^{\mathrm{\ensuremath{-}}1}$, and -1.46\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}5}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ ${\mathrm{K}}^{\mathrm{\ensuremath{-}}2}$, respectively, for the LO (\ensuremath{\Gamma}) mode. It is shown that the Raman linewidth variations with temperature can be fit to the predictions of a three- and four-phonon-interaction model. Comparison with earlier results from natural diamond is made.