Anomalous phonon redshift in K-doped BaFe$_2$As$_2$ iron pnictides

Abstract : The effect of K, Co, and P dopings on the lattice dynamics in the BaFe$_2$As$_2$ system is studied by infrared spectroscopy. We focus on the phonon at ∼ 253 cm$^{-1}$ , the highest energy in-plane infrared-active Fe-As mode in BaFe$_2$As$_2$. Our studies show that Co and P dopings lead to a blueshift of this phonon in frequency, which can be simply interpreted by the change in lattice parameters induced by doping. In sharp contrast, an unusual redshift of the same mode was observed in the K-doped compound, at odds with the above explanation. This anomalous behavior in K-doped BaFe$_2$As$_2$ is more likely associated with the coupling between lattice vibrations and other channels, such as charge or spin. This coupling scenario is also supported by the asymmetric line shape and intensity growth of the phonon in the K-doped compound.
Document type :
Journal articles
Complete list of metadatas

Cited literature [25 references]  Display  Hide  Download

https://hal-cea.archives-ouvertes.fr/cea-01497885
Contributor : Dominique Girard <>
Submitted on : Wednesday, March 29, 2017 - 2:21:02 PM
Last modification on : Tuesday, August 13, 2019 - 11:22:20 AM
Long-term archiving on : Friday, June 30, 2017 - 3:17:02 PM

File

PhysRevB.91.104510.pdf
Publisher files allowed on an open archive

Identifiers

Citation

B. Xu, Y. M. Dai, B. Shen, H. Xiao, Z. R. Ye, et al.. Anomalous phonon redshift in K-doped BaFe$_2$As$_2$ iron pnictides. Physical Review B : Condensed matter and materials physics, American Physical Society, 2015, 91, pp.104510. ⟨10.1103/PhysRevB.91.104510⟩. ⟨cea-01497885⟩

Share

Metrics

Record views

305

Files downloads

144