Intrinsic crystal phase separation in antiferromagnetic superconductor RbyFe2-xSe2: a diffraction study
arXiv:1204.5449 · doi:10.1088/0953-8984/24/43/435701
Abstract
The crystal and magnetic structures of the superconducting iron based chalcogenides RbyFe2-xSe2 have been studied by means of single crystal synchrotron x-ray and high resolution neutron powder diffraction in the temperature range 2-570 K. The ground state of the crystal is an intrinsically phase separated state with two distinct by symmetry phases. The main phase has the iron vacancy ordered \surd5x\surd5 superstructure (I4/m space group) with AFM ordered Fe spins. The minority phase does not have \surd5x\surd5-type of ordering and has smaller in plane lattice constant a and larger tetragonal c-axis and can be well described assuming the parent average vacancy disordered structure (I4/mmm space group) with the refined stoichiometry Rb0.60(5)(Fe1.10(5))Se)2. The minority phase amounts to 8-10% mass fraction. The unit cell volume of the minority phase is 3.2% smaller than the one of the main phase at T = 2 K and has quite different temperature dependence. The minority phase transforms to the main vacancy ordered phase on heating above the phase separation temperature T_P = 475 K. The spatial dimensions of the phase domains strongly increase above TP from 1000 Å to > 2500 Å due to the merging of the regions of the main phase that were separated by the second phase at low temperatures. Additional annealing of the crystals at the temperature T=488 K close to T_P for the long time drastically reduces the amount of the minority phase.
added additional figure and section on high T annealing
References in corpus (24)
- Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
- Fe-based high temperature superconductivity with Tc=31K bordering an insulating antiferromagnet in (Tl,K)FexSe2 Crystals
- A Novel Large Moment Antiferromagnetic Order in K0.8Fe1.6Se2 Superconductor
- Superconductivity at 32 K in single crystal RbFeSe}
- Synthesis and crystal growth of Cs0.8(FeSe0.98)2: a new iron-based superconductor with Tc=27K
- Phase Separation and Magnetic Order in K-doped Iron Selenide Superconductor
- Nanoscale phase separation in the iron chalcogenide superconductor K0.8Fe1.6Se2 as seen via scanning nanofocused x-ray diffraction
- Microstructure and Fe-vacancy ordering in the KFexSe2 superconducting system
- On the Structure of Vacancy Ordered Superconducting Alkali Metal Iron Selenide
- Intrinsic phase separation in superconducting K0.8Fe1.6Se2 (Tc= 31.8 K) single crystals
- Coexistence of superconductivity and antiferromagnetism in single crystals (A= K, Rb, Cs, Tl/K and Tl/Rb): evidence from magnetization and resistivity
- Nanoscale phase separation of antiferromagnetic order and superconductivity in KFeSe
- Iron vacancy superstructure and possible room temperature antiferromagnetic order in superconducting Cs_{y}Fe_{2-x}Se_2
- The critical line of two-flavor QCD at finite isospin or baryon densities from imaginary chemical potentials
- Cation vacancy order in the K0.8+xFe1.6-ySe2 system: five-fold cell expansion accommodates 20% tetrahedral vacancies
- Reciprocal-space structure and dispersion of the magnetic resonant mode in the superconducting phase of Rb(x)Fe(2-y)Se2 single crystals
- Superconducting properties of single-crystalline A_{x}Fe_{2-y}Se_{2} (A=Rb, K) studied using muon spin spectroscopy
- Antiferromagnetic order and superlattice structure in nonsuperconducting and superconducting RbyFe(1.6+x)Se2
- Imaging the coexistence of superconductivity and a charge density modulation in K0.73Fe1.67Se2 superconductor
- Charmonium spectral functions with the variational method in zero and finite temperature lattice QCD
- Room temperature antiferromagnetic order in superconducting X_yFe_{2-x}Se_ 2, (X= Rb, K): a powder neutron diffraction study
- Uniform Patterns of Fe Vacancy Ordering in the Kx(Fe,Co)2-ySe2 Superconductors
- Temperature and pressure evolution of the crystal structure of Ax(Fe1-ySe)2 (A = Cs, Rb, K) studied by synchrotron powder diffraction
- Magnetic-field tuned anisotropy in superconducting Rb(x)Fe(2-y)Se(2)
Cited by in corpus (18)
- The Unexpected Properties of Alkali Metal Iron Selenide Superconductors
- Phase relations in K_xFe_{2-y}Se_2 and the structure of superconducting K_xFe_2Se_2 via high-resolution synchrotron diffraction
- Spin fluctuations in iron pnictides and chalcogenides: From antiferromagnetism to superconductivity
- Evolution of precipitate morphology during heat treatment and its implications for the superconductivity in KxFe1.6+ySe2 single crystals
- Superconductivity and magnetism in RbxFe2-ySe2: Impact of thermal treatment on mesoscopic phase separation
- High resolution characterisation of microstructural evolution in RbFeSe crystals on annealing
- Bandwidth and Electron Correlation-Tuned Superconductivity in RbFe(SeS)
- Phase co-existence and structured diffuse scattering seen by X-ray 3D mapping of reciprocal space for Cs0.8Fe1.6Se2
- Compressibility and pressure-induced disorder in superconducting phase-separated Cs0.72Fe1.57Se2
- Structural, magnetic, and electronic evolution of the spin-ladder system BaFeSSe with isoelectronic substitution
- Two-dimensional Cs-vacancy superstructure in iron-based superconductor
- Field-induced transition of the magnetic ground state from A-type antiferromagnetic to ferromagnetic order in CsCo2Se2
- Pair-checkerboard antiferromagnetic order in -FeSe with ordered Fe vacancies
- Structure, superconductivity, and magnetism in Rb1-xFe1.6Se2-zSz
- Quenching Dependence on Superconductivity in the Synthesizing Process of Single Crystals of RbFeSe
- Formation of single-phase disordered CsxFe2-ySe2 at high pressure
- Superconducting dome and microstructure properties of Rb0.8Fe1.6+xSe2 superconductors
- Phase separation in iron chalcogenide superconductor Rb0.8+xFe1.6+ySe2 as seen by Raman light scattering and band structure calculations