Title: A comparative study for structural and electronic properties of single-crystal ScN
Author(s):

	R. Mohammad (Palestine Technical University, Applied Science College, WestBank, Palestine; Middle East Technical University, Physics Department, 06530 Ankara, Turkey) ,
	S. Katircioglu (Middle East Technical University, Physics Department, 06530 Ankara, Turkey)

A comparative study by FP-LAPW calculations based on DFT within LDA, PBE-GGA, EV_ex-PW_co-GGA, and EV_ex-GGA-LDA_co schemes is introduced for the structural and electronic properties of ScN in RS, ZB, WZ, and CsCl phases. According to all approximations used in this work, the RS phase is the stable ground state structure and makes a transition to CsCl phase at high transition pressure. While PBE-GGA and EV_ex-PW_co-GGA's have provided better structural features such as equilibrium lattice constant and bulk modulus, only EV_ex-PW_co-GGA and EV_ex-GGA-LDA_co's have given the non zero, positive indirect energy gap for RS-ScN, comparable with the experimental ones. The indirect band gap of ScN in RS phase is enlarged to the corresponding measured value by EV_ex-PW_co-GGA+U^SIC calculations in which the Coulomb self and exchange-correlation interactions of the localized d-orbitals of Sc have been corrected by the potential parameter of U. The EV_ex-PW_co-GGA calculations have also provided good results for the structural and electronic features of ScN in ZB, WZ, and CsCl phases comparable with the theoretical data available in the literature. EV_ex-PW_co-GGA and EV_ex-PW_co-GGA+U^SIC schemes are considered to be the best ones among the others when the structural and electronic features of ScN are aimed to be calculated by the same exchange-correlation energy approximations.

Key words: ScN, FP-LAPW, DFT, structural properties, electronic properties
PACS: 71.15.Mb, 71.15.Nc, 71.20.Nr, 71.18.+y

Full text [pdf, ps]

<< List of papers