Synthesis of Bulk FeTe1−x Se x (x = 0.1−0.5) at Ambient Pressure

Abstract

In this study, polycrystalline samples with nominal composition FeTe 1−x Se x (x = 0.1 − 0.5) were synthesized by solid-state reaction method at ambient pressure. In order to minimize oxidation, argon gas flow was maintained throughout the heat treatment. The phase formation of FeTe 1−x Se x samples was checked by X-ray diffraction (XRD). The polycrystalline FeTe 1−x Se x samples were indexed to a tetragonal structure with space group of P4/nmm. The lattice parameters a-and c-axes shrink significantly with the substitution of Se. As shown by the scanning electron microscope (SEM) images, the samples developed a plate-like grain structure gradually with the increase of Se concentration. Measurements of temperature dependence of magnetic moment showed that the onset of superconducting transition temperature, T c , increased with Se concentration. The T c is about 10.6 and 13.5 K for x = 0.1 and 0.5, respectively. All the samples exhibit ferromagnetic behavior as shown by the field-dependent magnetization measured at room temperature.

Fabrication of FeSe 0 . 5 Te 0 . 5 Superconducting Wires by an Ex Situ Powder-in-Tube Method

“…3 displays an enlarged view of the M-T curve of the as-drawn wire, and a T c of ∼ 13 K of its core is obtained. Besides, the T c of ∼ 13 K of the core of the as-drawn wire is close to the literature [4,10,12,14]. However, the values of T c of the Nb sheathand the core are largely decreased after heat treatment, with the superconducting transition of the core of even covered by the one of Nb sheath.…”

“…application fields [1][2][3][4][5][6][7]. Among the iron-based superconductors family, the FeSe composing of only ironchalcogenide layers holds the simplest crystal structure, which gives a favor for probing the mechanism of superconductivity of the iron-based superconductors [8].…”

Oyster Pearl-Shaped Ternary Iron Chalcogenide, FeSe0.5Te0.5, Films on FTO through Electrochemical Growth from the Exchange of Chalcogens Boosted the Enzyme-Free Urea-Sensing Ability toward Real Analytes

“…In comparison to metal hydroxides and oxides, transition metal chalcogenides 9 (TMCs) showed greater catalytic activity (higher redox activity) and superior conductivity. Iron chalcogenides are very promising because they are applicable in thermoelectrics, 10 magnetic semiconductors, 11 superconductors, 12 quantum dots, 13 sensors, 14 and photovoltaics. 15 The surprising finding of superconductivity in β-FeSe, 16 (TMA) 0.5 Fe 2 Se 2 , and FeTe 2 has attracted new interest.…”

Direct Microwave Synthesis of 11-Type Fe(Te,Se) Polycrystalline Superconductors with Enhanced Critical Current Density

“…The origin of this anomaly was attributed to the existence of tiny magnetic impurity of iron oxides inside the polycrystalline samples as reported previously. [40,41] The isothermal magnetization (𝑀 -𝐻) plots for both the samples at 2 K under a changing magnetic field from −7 T to 7 T are shown in Figs. 3(c) and 3(d).…”