Nematic fluctuations and phase transitions in LaFeAsO: A Raman scattering study
Date
Authors
Major Professor
Advisor
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Authors
Research Projects
Organizational Units
Ames National Laboratory is a government-owned, contractor-operated national laboratory of the U.S. Department of Energy (DOE), operated by and located on the campus of Iowa State University in Ames, Iowa.
For more than 70 years, the Ames National Laboratory has successfully partnered with Iowa State University, and is unique among the 17 DOE laboratories in that it is physically located on the campus of a major research university. Many of the scientists and administrators at the Laboratory also hold faculty positions at the University and the Laboratory has access to both undergraduate and graduate student talent.
Journal Issue
Is Version Of
Versions
Series
Department
Abstract
Raman scattering experiments on LaFeAsO with distinct antiferromagnetic (TAFM=140 K) and tetragonal-orthorhombic (TS=155 K) transitions show a quasielastic peak (QEP) in B2g symmetry (2 Fe tetragonal cell) that fades away below ∼TAFM and is ascribed to electronic nematic fluctuations. A scaling of the reported shear modulus with the T dependence of the QEP height rather than the QEP area indicates that magnetic degrees of freedom drive the structural transition. The large separation between TS and TAFM in LaFeAsO compared to BaFe2As2 manifests itself in slower dynamics of nematic fluctuations in the former.
Comments
This article is published as Kaneko, U. F., P. F. Gomes, A. F. García-Flores, J-Q. Yan, T. A. Lograsso, G. E. Barberis, D. Vaknin, and E. Granado. "Nematic fluctuations and phase transitions in LaFeAsO: A Raman scattering study." Physical Review B 96, no. 1 (2017): 014506. DOI: 10.1103/PhysRevB.96.014506. Posted with permission.