分子軌道計算によるリチウムリン酸塩ガラス中の酸素の局所構造と電子状態の評価

抄録

The validity of separating O1s photoelectron spectra of alkaline phosphate glasses into three peaks assigned to bridging, non-bridging and double-bonded oxygen atoms was discussed on the basis of the molecular orbital calculations by density functional method. Models used for the calculations were lithium metaphosphate chain clusters consisting of 2, 4 and 5 PO₄ units. Two oxygen atoms around a Li⁺ ion, non-bridging oxygen and double-bonded oxygen, were structurally indistinguishable, and were considered to be classified into the same terminal atoms. The O1s orbital energies of these terminal oxygen atoms were consistent to each other within 0.4eV. The variation in orbital energies probably results from inhomogeneous broadening caused by the statistically distributed surroundings around PO₄ units. From these results, it was concluded that in O1s photoelectron spectra of phosphate glasses, the separation of the lower binding energy side peak into two bands is not appropriate.