Raman spectroscopic features of the neutral vacancy in diamond from ab initio quantum-mechanical calculations. Issue 3 (21st December 2015)

• Record Type: Journal Article
• Authors: Baima, Jacopo; Zelferino, Alessandro; Olivero, Paolo; Erba, Alessandro; Dovesi, Roberto
• Is Part Of: Physical chemistry chemical physics. Volume 18:Issue 3(2016)
• Page Start: 1961
• Page End: 1968
• Publication Date: 2015-12-21
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c5cp06672g
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Ab initio calculations of the Raman spectrum of the neutral vacancy in diamond reproduce observed spectral features of irradiated diamond up to the first-order peak. Abstract : Quantum-mechanical ab initio calculations are performed to elucidate the vibrational spectroscopic features of a common irradiation-induced defect in diamond, i.e. the neutral vacancy. Raman spectra are computed analytically through a Coupled-Perturbed-Hartree–Fock/Kohn−Sham approach as a function of both different defect spin states and defect concentration. The experimental Raman features of defective diamond located in the 400−1300 cm −1 spectral range, i.e. below the first-order line of pristine diamond at 1332 cm −1, are well reproduced, thus corroborating the picture according to which, at low damage densities, this spectral region is mostly affected by non-graphitic sp 3 defects. No peaks above 1332 cm −1 are found, thus ruling out previous tentative assignments of different spectral features (at 1450 and 1490 cm −1 ) to the neutral vacancy. The perturbation introduced by the vacancy to the thermal nuclear motion of carbon atoms in the defective lattice is discussed in terms of atomic anisotropic displacement parameters (ADPs), computed from converged lattice dynamics calculations.