Anomalous Pressure Dependence of the Charge Density Wave and Fermi Surface Reconstruction in BaFe 2 Al 9
Year: 2025
Type: article
Abstract: We investigate the pressure evolution of charge density wave (CDW) order in the intermetallic compound BaFe_{2}Al_{9}, which undergoes a pronounced first-order CDW transition ∼112 K at ambient pressure. High-pressure electrical resistivity and magnetization measurements reveal a systematic enhancement of the CDW transition temperature (T_{CDW}) at a rate of ∼60 K/GPa, reaching 300 K under ∼3.2 GPa. The transition sharpness diminishes with pressure, indicating a crossover from first- to second-order behavior. Fermi liquid (FL) fits to the low-temperature resistivity reveal an increase in residual resistivity and a nonmonotonic evolution of the FL coefficient, indicating a pressure-induced Fermi surface (FS) reconstruction. Synchrotron x-ray diffraction reveals anisotropic lattice compression, a change in the compression trend of lattice parameters, and an abrupt change in microstrain at ∼3.6 GPa. Density functional theory calculations reveal pressure-induced flattening of quasi-two-dimensional FS sheets associated with the CDW nesting vector, consistent with enhanced nesting. These findings highlight the critical role of lattice strain and electronic structure evolution in stabilizing a high-temperature CDW phase, making BaFe_{2}Al_{9} a rare example of a three-dimensional material where pressure promotes rather than suppresses the CDW order.
Source: Physical Review Letters
DOI: 10.1103/dxzf-fx8k
Institutions: University of Sharjah, Fayoum University, Elettra-Sincrotrone Trieste S.C.p.A., Bharathidasan University, National Science and Technology Council, National Cheng Kung University, Heidelberg University, Kyushu Institute of Technology, Uppsala University, KTH Royal Institute of Technology, Tamil Nadu Open University, University of Doha for Science and Technology
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,750
Funders: Qatar Research, Development and Innovation Council, Indian Institute of Science, Elettra-Sincrotrone Trieste, University of Sharjah, Department of Science and Technology, Ministry of Science and Technology, India, Department of Atomic Energy, Government of India, Deutsche Forschungsgemeinschaft, Knut och Alice Wallenbergs Stiftelse, Vetenskapsrådet, European Research Council, Board of Research in Nuclear Sciences
Awards: G1310879877, G2468691801, G383039267, G5022728189, Topological magnetic textures for spintronics via machine learning, G5571276802, Spin-lattice dynamics simulations with first-principles accuracy, G6635049005, Spin current based microwave signale generators, sensors, and neural networks, Discovery and investigation of systems with coupled topological magnetism and shape-memory properties, NAISS
OpenAlex ID: W4416980784