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Spin waves and magnetic exchange interactions in insulating Rb(0.89)Fe(1.58)Se(2)
Miaoyin Wang1, Chen Fang, Dao-Xin Yao
1Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996-1200, USA.
Nature Communications
|December 8, 2011
Summary
Iron pnictide superconductors and alkaline iron selenide superconductors share similar magnetic coupling origins. This finding suggests a unified understanding of magnetism across diverse iron-based superconducting materials.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Solid State Chemistry
Background:
- Iron pnictide superconductors exhibit collinear antiferromagnetism with low Néel temperatures.
- Alkaline iron selenide superconductors, though isostructural, are insulators with block antiferromagnetic order and higher Néel temperatures.
Purpose of the Study:
- To investigate the magnetic interactions in insulating alkaline iron selenide superconductors.
- To compare magnetic properties between iron pnictides and iron selenides.
Main Methods:
- Analysis of spin wave spectra in Rb(0.89)Fe(1.58)Se(2) using a local moment Heisenberg Hamiltonian.
- Fitting spin wave data to determine magnetic coupling strengths.
Main Results:
- Spin waves in Rb(0.89)Fe(1.58)Se(2) are accurately described by a Heisenberg Hamiltonian.
- Next-nearest neighbor couplings in Rb(0.89)Fe(1.58)Se(2), (Ba,Ca,Sr)Fe(2)As(2), and Fe(1.05)Te are of comparable magnitude.
Conclusions:
- A common origin for magnetism is proposed for all iron-based superconductors.
- Despite differences in ground states and magnetic ordering, fundamental magnetic interactions are shared.
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