掺稀土元素(Y，La)的γ-Si3N4的电子结构和光学性质

采用基于密度泛函的平面赝势方法(PWP)和广义梯度近似(GGA)，计算了未掺杂和掺杂稀土(Y，La)的γ-Si₃N₄中N-Y(La)键的布居值和它们的键长、掺杂后能带结构和态密度.发现掺杂后的带隙要减小，并且可能形成新的半导体，这将为找到新的半导体提供一个方向.还进一步研究了掺杂稀土(Y，La)后的光学性质，掺杂后有更高的静态介电常数，可以作为新的介电材料和好的折射材料，这对于一定的光学元件有潜在的应用前景.

Electrical structures and optical properties of doped earth element (Y，La) in γ-Si3N4

The electronic structures and optical properties, the atomic population, bond lengths, band structures and density of states (DOS) of undoped and doped rare earth elements (Y, La) in γ-Si₃N₄ have been calculated by means of plane wave pseudo-potential method (PWP) with generalized gradient approximation (GGA). The gap after doping will decrease and enables the formation of new semiconductor，which affords to help finding new semiconductor. We researched optical properties after doping of rare earth elements (Y, La), and found that the static dielectric constant of doped γ-Si₃N₄ is much higher than that of the undoped material，which may serve as new dielectric and refractive material，and may have special applications in certain optical devices.