Back to Search
Start Over
Sr2Pt8−xAs: a layered incommensurately modulated metal with saturated resistivity
- Source :
- IUCrJ, Vol 5, Iss 4, Pp 470-477 (2018)
- Publication Year :
- 2018
- Publisher :
- International Union of Crystallography, 2018.
-
Abstract
- The high-pressure synthesis and incommensurately modulated structure are reported for the new compound Sr2Pt8−x As, with x = 0.715 (5). The structure consists of Sr2Pt3As layers alternating with Pt-only corrugated grids. Ab initio calculations predict a metallic character with a dominant role of the Pt d electrons. The electrical resistivity (ρ) and Seebeck coefficient confirm the metallic character, but surprisingly, ρ showed a near-flat temperature dependence. This observation fits the description of the Mooij correlation for electrical resistivity in disordered metals, originally developed for statistically distributed point defects. The discussed material has a long-range crystallographic order, but the high concentration of Pt vacancies, incommensurately ordered, strongly influences the electronic conduction properties. This result extends the range of validity of the Mooij correlation to long-range ordered incommensurately modulated vacancies. Motivated by the layered structure, the resistivity anisotropy was measured in a focused-ion-beam micro-fabricated well oriented single crystal. A low resistivity anisotropy indicates that the layers are electrically coupled and conduction channels along different directions are intermixed.
- Subjects :
- Materials science
composite materials
inorganic materials
Mooij correlation
010402 general chemistry
01 natural sciences
Biochemistry
Ab initio quantum chemistry methods
Electrical resistivity and conductivity
Seebeck coefficient
0103 physical sciences
platinum-based metallic compounds
General Materials Science
incommensurately modulated structure
010306 general physics
Anisotropy
lcsh:Science
density functional theory
Condensed matter physics
General Chemistry
Condensed Matter Physics
Thermal conduction
vacancies
Crystallographic defect
0104 chemical sciences
Density functional theory
lcsh:Q
Single crystal
Subjects
Details
- Language :
- English
- ISSN :
- 20522525
- Volume :
- 5
- Issue :
- 4
- Database :
- OpenAIRE
- Journal :
- IUCrJ
- Accession number :
- edsair.doi.dedup.....e4e02a83b5370ceb5f83e5870da9db81