EAPSI:Investigating the Electronic and Magnetic Properties of Composites with Trapped Electrons

Nandadasa Chandani N, Starkville MS

Investigators

Abstract

An ionic compound is a chemical compound in which positive and negative ions are held together by ionic bonds. The positively charged ions are called cations and the negatively charged ions are called anions. Electride is a unique class of ionic compound with nonreducible countercations and electrons as anions. These anionic electrons are neither associated with specific atom or bond nor fully delocalized, but they are localized within the crystal voids. Since these electrons are not bound to any ions, electrides have a great potential for cold emission in a low electric field for high-efficiency light-emitting devices like cold-cathode fluorescent lamps. Most of these electrides are sensitive to air and temperature, but recently several new layer structured two-dimensional electrides have been developed making the practical application of electrides possible. Two-dimensional electrides also attract scientists because of their unique electronic properties such as superconductivity and for the potential application for organic light-emitting diode (OLED) due to their low electron work function. Theoretical study of electrides is essential for developing new electrides for selecting candidate compounds with enhanced electronic properties. This research will be conducted with Dr. Sung Wng Kim, a noted expert in material science, at Center for Integrated Nanostructure Physics (CINAP), Sungkyunkwan University (SKKU), Suwon, Republic of Korea. Theoretical simulations will use the first-principles calculations based on the Density Functional Theory (DFT) as implemented in the Vienna Ab initio Simulation Package (VASP). Among layer-structure two-dimensional electrides, two carbides (Yttrium carbide - Y2C and Dysprosium carbide - Dy2C) and two nitrides (Strontium nitride - Sr2N and Barium nitride - Ba2N) have been selected for the proposed project. It is proposed to do theoretical calculations and compare with the experimental results obtained in the host research advisor's group. The proposed project will obtain structural, electronic, magnetic and surface properties of Y2C, Dy2C, Sr2N and Ba2N using first principles calculations to elucidate the relationship between structure and material properties of electrides. This award is funded in collaboration with the National Research Foundation of Korea.