First-principles study on the optical properties of NaNO2 in the ferroelectric and paraelectric phase

The full potential linearized augmented plane wave method within the genera lized gradient approximation was used to calculate the optical properties o f NaNO2, In order to understand the difference of optical properties betwee n the ferroelectric and paraelectric phase, the imaginary part of dielectri c function epsilon (2)(omega), the optical absorption coefficient I(omega) and the reflectivity R(omega) were calculated. The behavior of epsilon (2)( omega), I(omega) and R(omega) show that the ferroelectric NaNO2 is a very a nisotropic material and the optical properties in the ferroelectric phase h ave a higher anisotropy than those in the paraelectric phase. (C) 2001 Else vier Science Ltd. All rights reserved.