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Mydeen K, Jesche A, Meier-Kirchner K, Schwarz U, Geibel C, Rosner H, Nicklas M. Electron Doping of the Iron-Arsenide Superconductor CeFeAsO Controlled by Hydrostatic Pressure. Phys Rev Lett 2020; 125:207001. [PMID: 33258641 DOI: 10.1103/physrevlett.125.207001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 09/25/2020] [Accepted: 10/14/2020] [Indexed: 06/12/2023]
Abstract
In the iron-pnictide material CeFeAsO not only the Fe moments, but also the local 4f moments of the Ce order antiferromagnetically at low temperatures. We elucidate on the peculiar role of the Ce on the emergence of superconductivity. While application of pressure suppresses the iron SDW ordering temperature monotonously up to 4 GPa, the Ce-4f magnetism is stabilized until both types of magnetic orders disappear abruptly and a narrow SC dome develops. With further increasing pressure characteristics of a Kondo-lattice system become more and more apparent in the electrical resistivity. This suggests a connection of the emergence of superconductivity with the extinction of the magnetic order and the onset of Kondo screening of the Ce-4f moments.
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Affiliation(s)
- K Mydeen
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden
| | - A Jesche
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden
- Experimental Physics VI, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, 86135 Augsburg, Germany
| | - K Meier-Kirchner
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden
| | - U Schwarz
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden
| | - C Geibel
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden
| | - H Rosner
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden
| | - M Nicklas
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden
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Mydeen K, Kasinathan D, Koz C, Rößler S, Rößler UK, Hanfland M, Tsirlin AA, Schwarz U, Wirth S, Rosner H, Nicklas M. Pressure-Induced Ferromagnetism due to an Anisotropic Electronic Topological Transition in Fe_{1.08}Te. Phys Rev Lett 2017; 119:227003. [PMID: 29286759 DOI: 10.1103/physrevlett.119.227003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Indexed: 06/07/2023]
Abstract
A rapid and anisotropic modification of the Fermi-surface shape can be associated with abrupt changes in crystalline lattice geometry or in the magnetic state of a material. We show that such an electronic topological transition is at the basis of the formation of an unusual pressure-induced tetragonal ferromagnetic phase in Fe_{1.08}Te. Around 2 GPa, the orthorhombic and incommensurate antiferromagnetic ground state of Fe_{1.08}Te is transformed upon increasing pressure into a tetragonal ferromagnetic state via a conventional first-order transition. On the other hand, an isostructural transition takes place from the paramagnetic high-temperature state into the ferromagnetic phase as a rare case of a "type-0" transformation with anisotropic properties. Electronic-structure calculations in combination with electrical resistivity, magnetization, and x-ray diffraction experiments show that the electronic system of Fe_{1.08}Te is instable with respect to profound topological transitions that can drive fundamental changes of the lattice anisotropy and the associated magnetic order.
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Affiliation(s)
- K Mydeen
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - D Kasinathan
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - C Koz
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - S Rößler
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - U K Rößler
- Leibniz-Institut für Festkörper- und Werkstoffforschung IFW, Helmholtz Straße 20, 01171 Dresden, Germany
| | - M Hanfland
- ESRF, BP 220, F-38043 Grenoble Cedex 9, France
| | - A A Tsirlin
- Experimental Physics VI, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, 86135 Augsburg, Germany
| | - U Schwarz
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - S Wirth
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - H Rosner
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - M Nicklas
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
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Piva MM, Besser M, Mydeen K, Garitezi TM, Rosa PFS, Adriano C, Grant T, Fisk Z, Urbano RR, Nicklas M, Pagliuso PG. Combined external pressure and Cu-substitution studies on BaFe₂As₂ single crystals. J Phys Condens Matter 2015; 27:145701. [PMID: 25786492 DOI: 10.1088/0953-8984/27/14/145701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We report a combined study of external pressure and Cu-substitution on BaFe2As2 single crystals grown by the in-flux technique. At ambient pressure, the Cu-substitution is known to suppress the spin density wave (SDW) phase in pure BaFe2As2(T(SDW) ≈ 140 K) and to induce a superconducting (SC) dome with a maximum transition temperature T(c)(max) ≃ 4.2 K. This T(c)(max) is much lower than the T(c) ∼ 15-28 K achieved in the case of Ru, Ni and Co substitutions. Such a lower T(c) is attributed to a Cu(2+) magnetic pair-breaking effect. The latter is strongly suppressed by applied pressure, as shown herein, Tc can be significantly enhanced by applying high pressures. In this work, we investigated the pressure effects on Cu(2+) magnetic pair-breaking in the BaFe(2-x)Cu(x)As2 series. Around the optimal concentration (x(opd) = 0.11), all samples showed a substantial increase of T(c) as a function of pressure. Yet for those samples with a slightly higher doping level (over-doped regime), T(c) presented a dome-like shape with maximum T(c) ≃ 8 K. Remarkably interesting, the under-doped samples, e.g. x = 0.02 display a maximum pressure induced T(c) ≃ 30 K which is comparable to the maximum T(c)'s found for the pure compound under external pressures. Furthermore, the magnetoresistance effect as a function of pressure in the normal state of the x = 0.02 sample also presented an evolution consistent with the screening of the Cu(2+) local moments. These findings demonstrate that the Cu(2+) magnetic pair-breaking effect is completely suppressed by applying pressure in the low concentration regime of Cu(2+) substituted BaFe2As2.
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Affiliation(s)
- M M Piva
- Instituto de Física 'Gleb Wataghin', UNICAMP, Campinas-SP 13083-859, Brazil. Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, D-01187 Dresden, Germany
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Rosa PFS, Adriano C, Garitezi TM, Piva MM, Mydeen K, Grant T, Fisk Z, Nicklas M, Urbano RR, Fernandes RM, Pagliuso PG. Possible unconventional superconductivity in substituted BaFe2As2 revealed by magnetic pair-breaking studies. Sci Rep 2014; 4:6252. [PMID: 25176407 PMCID: PMC4150111 DOI: 10.1038/srep06252] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 07/15/2014] [Indexed: 11/28/2022] Open
Abstract
The possible existence of a sign-changing gap symmetry in BaFe2As2-derived superconductors (SC) has been an exciting topic of research in the last few years. To further investigate this subject we combine Electron Spin Resonance (ESR) and pressure-dependent transport measurements to investigate magnetic pair-breaking effects on BaFe1.9M0.1As2 (M = Mn, Co, Cu, and Ni) single crystals. An ESR signal, indicative of the presence of localized magnetic moments, is observed only for M = Cu and Mn compounds, which display very low SC transition temperature (Tc) and no SC, respectively. From the ESR analysis assuming the absence of bottleneck effects, the microscopic parameters are extracted to show that this reduction of Tc cannot be accounted by the Abrikosov-Gorkov pair-breaking expression for a sign-preserving gap function. Our results reveal an unconventional spin- and pressure-dependent pair-breaking effect and impose strong constraints on the pairing symmetry of these materials.
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Affiliation(s)
- P F S Rosa
- 1] Instituto de Física "Gleb Wataghin", UNICAMP, Campinas-SP, 13083-859, Brazil [2] University of California, Irvine, California 92697-4574, USA
| | - C Adriano
- Instituto de Física "Gleb Wataghin", UNICAMP, Campinas-SP, 13083-859, Brazil
| | - T M Garitezi
- Instituto de Física "Gleb Wataghin", UNICAMP, Campinas-SP, 13083-859, Brazil
| | - M M Piva
- 1] Instituto de Física "Gleb Wataghin", UNICAMP, Campinas-SP, 13083-859, Brazil [2] Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, D-01187 Dresden, Germany
| | - K Mydeen
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, D-01187 Dresden, Germany
| | - T Grant
- University of California, Irvine, California 92697-4574, USA
| | - Z Fisk
- University of California, Irvine, California 92697-4574, USA
| | - M Nicklas
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, D-01187 Dresden, Germany
| | - R R Urbano
- Instituto de Física "Gleb Wataghin", UNICAMP, Campinas-SP, 13083-859, Brazil
| | - R M Fernandes
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455, USA
| | - P G Pagliuso
- Instituto de Física "Gleb Wataghin", UNICAMP, Campinas-SP, 13083-859, Brazil
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