Abstract
Using ab initio molecular dynamics we investigate the electronic and lattice structure of A Fe2 As2 (A=Ca,Sr,Ba) under pressure. We find that the structural phase transition (orthorhombic to tetragonal symmetry) is always accompanied by a magnetic phase transition in all the compounds while the nature of the transitions is different for the three systems. Our calculations explain the origin of the existence of a collapsed tetragonal phase in CaFe2 As2 and its absence in BaFe2 As2. We argue that changes in the Fermi-surface nesting features dominate the phase transitions under pressure rather than spin frustration or a Kondo scenario. The consequences for superconductivity are discussed.
| Original language | English |
|---|---|
| Article number | 094530 |
| Journal | Physical Review B - Condensed Matter and Materials Physics |
| Volume | 80 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - Sep 30 2009 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Condensed Matter Physics
- Electronic, Optical and Magnetic Materials
Cite this
Microscopic origin of pressure-induced phase transitions in the iron pnictide superconductors A Fe2 As2 : An ab initio molecular dynamics study. / Zhang, Yu Zhong; Kandpal, Hem C.; Opahle, Ingo; Jeschke, Harald Olaf; Valentí, Roser.
In: Physical Review B - Condensed Matter and Materials Physics, Vol. 80, No. 9, 094530, 30.09.2009.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Microscopic origin of pressure-induced phase transitions in the iron pnictide superconductors A Fe2 As2
T2 - An ab initio molecular dynamics study
AU - Zhang, Yu Zhong
AU - Kandpal, Hem C.
AU - Opahle, Ingo
AU - Jeschke, Harald Olaf
AU - Valentí, Roser
PY - 2009/9/30
Y1 - 2009/9/30
N2 - Using ab initio molecular dynamics we investigate the electronic and lattice structure of A Fe2 As2 (A=Ca,Sr,Ba) under pressure. We find that the structural phase transition (orthorhombic to tetragonal symmetry) is always accompanied by a magnetic phase transition in all the compounds while the nature of the transitions is different for the three systems. Our calculations explain the origin of the existence of a collapsed tetragonal phase in CaFe2 As2 and its absence in BaFe2 As2. We argue that changes in the Fermi-surface nesting features dominate the phase transitions under pressure rather than spin frustration or a Kondo scenario. The consequences for superconductivity are discussed.
AB - Using ab initio molecular dynamics we investigate the electronic and lattice structure of A Fe2 As2 (A=Ca,Sr,Ba) under pressure. We find that the structural phase transition (orthorhombic to tetragonal symmetry) is always accompanied by a magnetic phase transition in all the compounds while the nature of the transitions is different for the three systems. Our calculations explain the origin of the existence of a collapsed tetragonal phase in CaFe2 As2 and its absence in BaFe2 As2. We argue that changes in the Fermi-surface nesting features dominate the phase transitions under pressure rather than spin frustration or a Kondo scenario. The consequences for superconductivity are discussed.
UR - http://www.scopus.com/inward/record.url?scp=70349971155&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=70349971155&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.80.094530
DO - 10.1103/PhysRevB.80.094530
M3 - Article
AN - SCOPUS:70349971155
VL - 80
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 1098-0121
IS - 9
M1 - 094530
ER -