Microstructural properties of K0.8 Fe1.6 S2, K0.8 Fe1.75 Se2-y Sy(0 ≤ y ≤ 2) and K0.8 Fe1.5+x S2(0 < x ≤ 0.5) single crystals

Y. Cai; Z. Wang; Z. W. Wang; Z. A. Sun; H. X. Yang; H. F. Tian; C. Ma; B. Zhang; J. Q. Li

doi:10.1209/0295-5075/103/37010

All issues

Volume 103 / No 3 (August 2013)

EPL, 103 3 (2013) 37010

Abstract

Issue		EPL Volume 103, Number 3, August 2013


Article Number		37010
Number of page(s)		6
Section		Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
DOI		https://doi.org/10.1209/0295-5075/103/37010
Published online		30 August 2013

EPL, 103 (2013) 37010

Microstructural properties of K_0.8 Fe_1.6 S₂, K_0.8 Fe_1.75 Se_2-y S_y(0 ≤ y ≤ 2) and K_0.8 Fe_1.5+x S₂(0 < x ≤ 0.5) single crystals

Y. Cai¹, Z. Wang¹, Z. W. Wang¹, Z. A. Sun¹^,2, H. X. Yang¹^(a), H. F. Tian¹, C. Ma¹, B. Zhang² and J. Q. Li¹^(b)

¹ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences Beijing 100190, PRC
² School of Materials Science and Engineering, Hefei University of Technology - No. 193, Tunxi Road, Anhui Province, Hefei 230009, PRC

^(a) hxyang@aphy.iphy.ac.cn
^(b) ljq@aphy.iphy.ac.cn

Received: 28 June 2013
Accepted: 5 August 2013

Abstract

The structural features of the antiferromagnetic K_0.8Fe_1.6S₂ have been studied in the temperature range from 300 K up to 700 K by means of in situ transmission electron microscopy (TEM). The superstructure with a wave vector $\textbf{q}_{1}=1/5(3\textbf{a}^*+\textbf{b}^*)$ originating from a Fe-vacancy order has been clearly observed; moreover, the structural analysis shows that K_0.8Fe_1.6S₂ undergoes a transition from the Fe-vacancy order to disorder at about 585 K. The S substitution effect on the phase separation and superconductivity in the K_0.8Fe_1.75Se_2−yS_y materials has been systematically investigated by SEM and TEM structural analyses, as well as by electrical resistivity measurements. Our experimental results reveal that the S element adopts a homogeneous distribution in all investigated materials, and the essential phase-separation nature is very similar to what was observed in the K_0.8Fe_1.75Se₂ superconductor. A phase-separated state formed by the coexistence of two Fe-vacancy orders with wave vectors $\textbf{q}_{1}=1/5(3\textbf{a}^*+\textbf{b}^*)$ and $\textbf{q}_{3}=1/4(3\textbf{a}^*+\textbf{b}^*)$ in K_0.8Fe_1.5+xS₂ (0 < x < 0.1) has been briefly discussed.

PACS: 74.70.Xa – Pnictides and chalcogenides / 61.72.jd – Vacancies / 61.05.J- – Electron diffraction and scattering

© EPLA, 2013

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.