Phonon–phonon interactions in (Lu, Y)Ni2B2C Original Research Article

The temperature dependence of the Δ4 acoustic and optic mode, measured at q=(0.5,0,0) in LuNi2B2C, YNi2B2C were extended to 1000 K and new measurements on the mixed compound, Y0.5Lu0.5Ni2B2C, were undertaken to explore the mode coupling in these materials. The temperature behavior of each is different and cannot be explained by a simple mode coupling scheme of the acoustic and optic modes.