Structural phase transition below 250 K in superconducting K0.75Fe1.75Se2
A. Ignatov, A. Kumar, P. Lubik, R. H. Yuan, W. T. Guo, N. L. Wang, K. Rabe, G. Blumberg
DOI 10.1103/PhysRevB.86.134107 · Physical Review B
Active bibliographic source — not scientific approval
Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.
Abstract
Vibrational properties of iron-chalcogenide superconductor K0.75Fe1.75Se2 with Tc∼ 30 K have been measured by Raman and optical spectroscopies over the temperature range 3–300 K. The sample undergoes I4/m→I4 structural phase transition accompanied by loss of inversion symmetry at T1, below 250 K, observed as the appearance of new fully symmetric Raman mode at ∼165 cm−1. Small vibration mode anomalies are also observed at T2∼ 160 K. From first-principles vibrational analysis of antiferromagnetic K0.8Fe1.6Se2 utilizing pseudopotentials all observed Raman and infrared modes have been assigned and the displacement patterns of the new Raman mode identified as involving predominantly the Se atoms.
Source-reported materials — not catalogue approval
| Formula | Reported Tc (K) | Pressure (GPa) | Type |
|---|---|---|---|
| K0.75Fe1.75Se2 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 30 | Pressure not reported | unknown |
| K0.8Fe1.6Se2 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 30 | Pressure not reported | unknown |
Similar papers
Electronic Identification of the Parental Phases and Mesoscopic Phase Separation of KxFe2−ySe2 Superconductors
similarity 0.96F. Chen et al.
Source status unknown — claims are unverified
Pressure dependence of superconductivity in low- and high-Tc phases of (NH3)yNaxFeSe
similarity 0.96Takahiro Terao et al.
Source status unknown — claims are unverified
Superconductivity and magnetic properties of single crystals of K0.75Fe1.66Se2 and Cs0.81Fe1.61Se2
similarity 0.95J. J. Ying et al.
Source status unknown — claims are unverified
Superconducting critical fields of single-crystalline K0.73Fe1.68Se2
similarity 0.95M. I. Tsindlekht et al.
Source status unknown — claims are unverified
Pressure-Driven Quantum Criticality in Iron-Selenide Superconductors
similarity 0.95Jing Guo et al.
Source status unknown — claims are unverified
Superconductivity at 32 K in single-crystalline RbxFe2−ySe2
similarity 0.95A. F. Wang et al.
Source status unknown — claims are unverified