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Title: Experimental and theoretical investigations of the polar intermetallics SrPt{sub 3}Al{sub 2} and Sr{sub 2}Pd{sub 2}Al

Abstract

SrPt{sub 3}Al{sub 2}, a CaCu{sub 5} relative (P6/mmm; a = 566.29(3), c = 389.39(3) pm; wR{sub 2} = 0.0202, 121 F{sup 2} values, 9 parameters), and Sr{sub 2}Pd{sub 2}Al, isostructural to Ca{sub 2}Pt{sub 2}Ge (Fdd2; a = 1041.45(5), b = 1558.24(7), c = 604.37(3) pm; wR{sub 2} = 0.0291, 844 F{sup 2} values, 25 parameters) have been prepared from the elements. The crystal structures have been investigated by single crystal X-ray diffraction. Structural relaxation confirmed the electronic stability of SrPt{sub 3}Al{sub 2}, while orthorhombic Sr{sub 2}Pd{sub 2}Al might be a metastable polymorph as it is energetically competitive to its monoclinic variant. Both compounds are predicted to be metallic conductors as their density-of-states (DOS) are non-zero at the Fermi level. COHP bonding analysis coupled with Bader effective charge analysis suggest that the title compounds are polar intermetallic phases in which strong Pt–Al and Pd–Al covalent bonds are present, while a significant electron transfer from Sr atoms to the [Pt{sub 3}Al{sub 2}]{sup δ–} or [Pd{sub 2}Al]{sup δ–} network is found. - Graphical abstract: Chains of Pd atoms in the crystal structure of Sr{sub 2}Pd{sub 2}Al get connected by Al atoms in the shape of a distorted tetrahedra. The band structure calculations confirmmore » weak Pd–Pd interactions. - Highlights: • SrPt{sub 3}Al{sub 2} and Sr{sub 2}Pd{sub 2}Al discovered and crystallographically investigated. • DFT predicts the here reported orthorhombic Sr{sub 2}Pd{sub 2}Al to be competitive in energy to the presently unknown monoclinic Sr{sub 2}Pd{sub 2}Al. • Bader charge analysis indicates SrPt{sub 3}Al{sub 2} and Sr{sub 2}Pd{sub 2}Al are polar intermetallics.« less

Authors:
;  [1]; ;  [2];  [1]
  1. Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 28/30, 48149 Münster (Germany)
  2. Institut für Anorganische Chemie, RWTH Aachen, Landoltweg 1, D-52074 Aachen (Germany)
Publication Date:
OSTI Identifier:
22658038
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 242; Journal Issue: Part 1; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ALUMINIUM ALLOYS; CHEMICAL BONDS; CRYSTALS; ELECTRON TRANSFER; EXPERIMENTAL DATA; FERMI LEVEL; INTERMETALLIC COMPOUNDS; MONOCLINIC LATTICES; ORTHORHOMBIC LATTICES; PALLADIUM ALLOYS; PLATINUM ALLOYS; STRONTIUM ALLOYS; X RADIATION; X-RAY DIFFRACTION

Citation Formats

Stegemann, Frank, Benndorf, Christopher, Touzani, Rachid St., Fokwa, Boniface P.T., and Janka, Oliver. Experimental and theoretical investigations of the polar intermetallics SrPt{sub 3}Al{sub 2} and Sr{sub 2}Pd{sub 2}Al. United States: N. p., 2016. Web. doi:10.1016/J.JSSC.2016.07.019.
Stegemann, Frank, Benndorf, Christopher, Touzani, Rachid St., Fokwa, Boniface P.T., & Janka, Oliver. Experimental and theoretical investigations of the polar intermetallics SrPt{sub 3}Al{sub 2} and Sr{sub 2}Pd{sub 2}Al. United States. doi:10.1016/J.JSSC.2016.07.019.
Stegemann, Frank, Benndorf, Christopher, Touzani, Rachid St., Fokwa, Boniface P.T., and Janka, Oliver. Sat . "Experimental and theoretical investigations of the polar intermetallics SrPt{sub 3}Al{sub 2} and Sr{sub 2}Pd{sub 2}Al". United States. doi:10.1016/J.JSSC.2016.07.019.
@article{osti_22658038,
title = {Experimental and theoretical investigations of the polar intermetallics SrPt{sub 3}Al{sub 2} and Sr{sub 2}Pd{sub 2}Al},
author = {Stegemann, Frank and Benndorf, Christopher and Touzani, Rachid St. and Fokwa, Boniface P.T. and Janka, Oliver},
abstractNote = {SrPt{sub 3}Al{sub 2}, a CaCu{sub 5} relative (P6/mmm; a = 566.29(3), c = 389.39(3) pm; wR{sub 2} = 0.0202, 121 F{sup 2} values, 9 parameters), and Sr{sub 2}Pd{sub 2}Al, isostructural to Ca{sub 2}Pt{sub 2}Ge (Fdd2; a = 1041.45(5), b = 1558.24(7), c = 604.37(3) pm; wR{sub 2} = 0.0291, 844 F{sup 2} values, 25 parameters) have been prepared from the elements. The crystal structures have been investigated by single crystal X-ray diffraction. Structural relaxation confirmed the electronic stability of SrPt{sub 3}Al{sub 2}, while orthorhombic Sr{sub 2}Pd{sub 2}Al might be a metastable polymorph as it is energetically competitive to its monoclinic variant. Both compounds are predicted to be metallic conductors as their density-of-states (DOS) are non-zero at the Fermi level. COHP bonding analysis coupled with Bader effective charge analysis suggest that the title compounds are polar intermetallic phases in which strong Pt–Al and Pd–Al covalent bonds are present, while a significant electron transfer from Sr atoms to the [Pt{sub 3}Al{sub 2}]{sup δ–} or [Pd{sub 2}Al]{sup δ–} network is found. - Graphical abstract: Chains of Pd atoms in the crystal structure of Sr{sub 2}Pd{sub 2}Al get connected by Al atoms in the shape of a distorted tetrahedra. The band structure calculations confirm weak Pd–Pd interactions. - Highlights: • SrPt{sub 3}Al{sub 2} and Sr{sub 2}Pd{sub 2}Al discovered and crystallographically investigated. • DFT predicts the here reported orthorhombic Sr{sub 2}Pd{sub 2}Al to be competitive in energy to the presently unknown monoclinic Sr{sub 2}Pd{sub 2}Al. • Bader charge analysis indicates SrPt{sub 3}Al{sub 2} and Sr{sub 2}Pd{sub 2}Al are polar intermetallics.},
doi = {10.1016/J.JSSC.2016.07.019},
journal = {Journal of Solid State Chemistry},
number = Part 1,
volume = 242,
place = {United States},
year = {Sat Oct 15 00:00:00 EDT 2016},
month = {Sat Oct 15 00:00:00 EDT 2016}
}