Hybrid-Density Functional Calculations of Structural, Electronic, Magnetic, and Thermodynamic Properties of alpha-Cu2P2O7

• We present a comparative study (using PBE, PBE0, and HSE functionals) of electronic and atomic structure, magnetism, and phonon dispersion relations of a-Cu2P2O7. Four possible magnetic configurations are considered, FM, AFM-1, AFM-2, and AFM-3. The calculations reveal that a-Cu(2)P2O(7) is mechanically and thermodynamically stable. The elastic moduli indicate a weak resistance of the compound to volume and shear deformations. The electronic structure at the valence band maximum is dominated by O, with a small admixture of Cu-d(x2-y2) states. The conduction band results from the hybridization between Cu and O states which, in the case of AFM-2, produces the largest band gap of 3.966 eV and the smallest magnetic moment of +/- 0.785 m B on Cu. AFM-2 is found to be the lowest-energy structure that may be viewed as consisting of quasi-one-dimensional Cu1 Cu-2 Cu-3 Cu-4 chains along the b axis; the antiferromagnetism is due to two identical Cu O Cu paths with a bond angle of 100.301 ffi. The phonon spectra exhibit four distinct frequency ranges corresponding to different vibrational modes of ions and ionic groups. Thus, a quantitative description of the structural, electronic, and magnetic properties of alpha-Cu(2)P2O(7) is possible using the HSE hybrid functional, which enables computational studies of transition metal pyro compounds.

Ämnesord

NATURVETENSKAP  -- Fysik -- Den kondenserade materiens fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Condensed Matter Physics (hsv//eng)

Nyckelord

copper pyrophosphate

hybrid-functional calculations

elastic properties

electronic structure

antiferromagnetism

phonon dispersion relations

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