Tuning topological disorder in MgB${}_2$

Abstract

We carried out Raman measurements on neutron-irradiated and Al-doped MgB${}_2$ samples. The irradiation-induced topological disorder causes an unexpected appearance of high frequency spectral structures, similar to those observed in lightly Al-doped samples. Our results show that disorder-induced violations of the selection rules are responsible for the modification of the Raman spectrum in both irradiated and Al-doped samples. Theoretical calculations of the phonon density of states support this hypothesis, and demonstrate that the high frequency structures arise mostly from contributions at $\mathbf{q}\ne 0$ of the E${}_{2g}$ phonon mode.

4 pages, 4 figures

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Cited by in corpus (6)

• Anharmonic effects in MgB2? A comparative inelastic X-ray scattering and Raman study
• Ultrafast Hot Phonon Dynamics in MgB${}_2$ Driven by Anisotropic Electron-Phonon Coupling
• Intraband versus interband scattering rate effects in neutron irradiated MgB2
• Raman spectroscopy study of the interface structure in (CaCuO2)n/(SrTiO3)m superlattices
• Vibrational spectrum of solid picene (C_22H_14)
• Two-bands superconductivity with intra- and interband pairing for synthetic superlattices