Spectral and quantum-mechanical study of electronic structure of ultradispersed calcium hydroxyapatite

• Дата: 2002
• Автори: Shpak, A.P., Karbovskii, V.L., Vakhney, A.G., Kluyenko, L.P.
• Формат: Стаття
• Мова: English
• Опубліковано: Інститут хімії поверхні ім. О.О. Чуйка НАН України 2002
• Назва видання: Поверхность
• Теми: Surface properties of inorganic materials
• Онлайн доступ: https://nasplib.isofts.kiev.ua/handle/123456789/126352
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Цитувати: Spectral and quantum-mechanical study of electronic structure of ultradispersed calcium hydroxyapatite / A.P. Shpak, V.L. Karbovskii, A.G. Vakhney, L.P. Kluyenko // Поверхность. — 2002. — Вип. 7-8. — С. 57-68. — Бібліогр.: 12 назв. — англ.

The regularities of electronic structure of calcium hydroxyapatite samples of different genealogy were investigated by X-ray, IR spectroscopy methods and by quantum-mechanical calculations - Xa and LMTO (methods of the band theory). The evolution of valence band and charge states of atoms is described. It was established that distribution of p- and d-electronic states of calcium in samples of calcium hydroxyapatite of different origin is practically identical. Beside a high ionic component, covalent and hydrogen bonds are present in calcium hydroxyapatite. The indirect metal-metal interaction is observed in a metal sublattice. It was shown that a sublattice of the phosphatic tetrahedra determines the shape and main features of a valence band of calcium hydroxyapatite. The lack of a part of calcium ions in the nonstoichiometric samples results in weakening of P-O bond within a mirror plane. An influence of the crystal-ultradispersed state transition on the shaping of X-ray emission spectra was first investigated. Considerable localisation of metal d-states is observed in the ultradispersed hydroxyapatite samples.