Dresden 2014 – scientific programme

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DS: Fachverband Dünne Schichten

DS 20: Focus Session: Emerging oxide semiconductors I (jointly with HL, DF, O)

DS 20.2: Talk

Wednesday, April 2, 2014, 10:00–10:15, POT 081

Phonon properties of Copper-Oxide phases from first principles — •Marcel Giar, Markus Heinemann, and Christian Heiliger — I. Physikalisches Institut, Justus-Liebig-University, D-35392 Giessen, Germany

We present ab initio investigations on phonon properties of the copper-oxide phases Cu₂O, CuO, and Cu₄O₃. Phonon bandstructure and density of states for all three phases are derived from a supercell small displacement method. This method relies on displacing atom(s) within a supercell and calculating resulting forces on all other atoms. As copper-oxides exhibit polar bonding the splitting of the LO and TO modes at the Γ point must be properly taken into account. We derive these splittings from Born effective charges and the dielectric tensor which enter the non-analytical contributions to the dynamical matrix in the limit q → 0.