(中南大學(xué) 物理科學(xué)與技術(shù)學(xué)院，長沙 410083)
摘 要: 利用基于密度泛函第一性原理的GGA方法，研究ZnRh2O4的電子結(jié)構(gòu)和光學(xué)性質(zhì)。計算結(jié)果表明：ZnRh2O4具有明顯的半導(dǎo)體能帶結(jié)構(gòu)特征，其帶隙寬度為1.084 eV，且在費米能級附近的態(tài)主要由Rh的4d態(tài)構(gòu)成。ZnRh2O4的靜態(tài)介電常數(shù)為8.215，靜態(tài)折射率為2.866，介電函數(shù)吸收邊位于1.0 eV附近。在能量為0~8.44 eV區(qū)域，ZnRh2O4的反射系數(shù)隨著能量的升高而逐漸增大；隨后隨能量的增大而逐漸減小；在能量為11.98 eV時，達(dá)到極小值，然后隨能量的增大，再次逐漸增大；在能量為13.762 eV時，再次達(dá)極大值, 隨后反射系數(shù)陡降；ZnRh2O4的吸收系數(shù)的數(shù)量級達(dá)105 cm−1，且吸收主要發(fā)生在低能區(qū)，其電子能量損失譜的共振峰在14.226 eV處，與此能量時反射系數(shù)的陡降相對應(yīng)。
關(guān)鍵字: ZnRh2O4；電子結(jié)構(gòu)；光學(xué)性質(zhì)；第一性原理；介電常數(shù)；反射系數(shù)；吸收系數(shù)；能量損失
optical properties of ZnRh2O4
（School of Physical Science and Technology, Central South University, Changsha 410083, China）
Abstract:The first-principles calculations were carried out to investigate the electronic structure and optical properties of ZnRh2O4 using the method of the generalized gradient approximation (GGA) based on density functional theory. The results show that the band structure of ZnRh2O4 is a kind of semi-conducting material with wide-band gap of 1.084 eV. Near the Fermi level, Rh 4d is derived bands. The static dielectric constant of ZnRh2O4 is 8.215, and the static refractive index is 2.866. For the imaginary part of dielectric constant, the absorption starts at about 1.0 eV. When the energy is 0−8.44 eV, the reflection index increases with increasing energy, and decreases to the minimum till 11.98 eV, and then increases with the increase of the energy again till 13.762 eV. There is an abrupt reduction when the energy is a little higher than 13.762 eV, which corresponds to the peak of electron energy loss spectrum (EELS). The absorption coefficient is as large as 105 cm−1, and the absorption mainly locates in the low energy region.
Key words: ZnRh2O4; electronic structure; optical properties; first-principles; dielectric function; refractive index; absorption coefficient; energy loss
