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Title: First-principles study of Se-intercalated graphite

Abstract

Se-intercalated graphite compounds (Se-GICs) are considered as promising candidates for room-temperature thermoelectric cooling devices. Here the authors analyze the crystallographic structure and electronic properties of these materials within the framework of density-functional theory. First, the Adaptive-Coordinate Real-space Electronic Structure (ACRES) code is used to determine the stable structure of a representative stage-2 Se-GIC by relaxing atomic positions. The stable configuration is found to be a pendant-type structure, in which each selenium is bonded covalently to two atoms within the same carbon layer, causing a local distortion of the in-plane conjugation of the graphite. Then, they use the full potential linearized augmented plane wave (FP-LAPW) method to calculate the electronic band structure of the material and discuss its properties. Near the Fermi energy E{sub F}, there are wide bands originating from the host graphitic electronic structure and a few very narrow bands mainly of Se 4p character. The latter bands contribute to high peaks in the density of states close to E{sub F}. They show that this feature, although typical of many good thermoelectrics, does not necessarily imply high thermopower in the case of Se-GICs.

Authors:
; ; ;
Publication Date:
Research Org.:
Sandia National Labs., Albuquerque, NM (US); Sandia National Labs., Livermore, CA (US)
Sponsoring Org.:
US Department of Energy (US)
OSTI Identifier:
755605
Report Number(s):
SAND2000-1198J
TRN: AH200021%%50
DOE Contract Number:  
AC04-94AL85000
Resource Type:
Journal Article
Journal Name:
Physical Review B
Additional Journal Information:
Other Information: Submitted to Physical Review B; PBD: 11 May 2000
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 30 DIRECT ENERGY CONVERSION; SELENIUM; CLATHRATES; GRAPHITE; THERMOELECTRIC REFRIGERATORS; CRYSTAL STRUCTURE; ELECTRICAL PROPERTIES; ELECTRONIC STRUCTURE

Citation Formats

BARTKOWIAK,M., MODINE,NORMAND A., SOFO,J.O., and MAHAN,G.D. First-principles study of Se-intercalated graphite. United States: N. p., 2000. Web.
BARTKOWIAK,M., MODINE,NORMAND A., SOFO,J.O., & MAHAN,G.D. First-principles study of Se-intercalated graphite. United States.
BARTKOWIAK,M., MODINE,NORMAND A., SOFO,J.O., and MAHAN,G.D. Thu . "First-principles study of Se-intercalated graphite". United States. https://www.osti.gov/servlets/purl/755605.
@article{osti_755605,
title = {First-principles study of Se-intercalated graphite},
author = {BARTKOWIAK,M. and MODINE,NORMAND A. and SOFO,J.O. and MAHAN,G.D.},
abstractNote = {Se-intercalated graphite compounds (Se-GICs) are considered as promising candidates for room-temperature thermoelectric cooling devices. Here the authors analyze the crystallographic structure and electronic properties of these materials within the framework of density-functional theory. First, the Adaptive-Coordinate Real-space Electronic Structure (ACRES) code is used to determine the stable structure of a representative stage-2 Se-GIC by relaxing atomic positions. The stable configuration is found to be a pendant-type structure, in which each selenium is bonded covalently to two atoms within the same carbon layer, causing a local distortion of the in-plane conjugation of the graphite. Then, they use the full potential linearized augmented plane wave (FP-LAPW) method to calculate the electronic band structure of the material and discuss its properties. Near the Fermi energy E{sub F}, there are wide bands originating from the host graphitic electronic structure and a few very narrow bands mainly of Se 4p character. The latter bands contribute to high peaks in the density of states close to E{sub F}. They show that this feature, although typical of many good thermoelectrics, does not necessarily imply high thermopower in the case of Se-GICs.},
doi = {},
journal = {Physical Review B},
number = ,
volume = ,
place = {United States},
year = {2000},
month = {5}
}