Comparative study of superconducting and normal-state anisotropy in 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Fe</mml:mi><mml:mrow><mml:mn>1</mml:mn><mml:mo>+</mml:mo><mml:mi>y</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mi>Te</mml:mi><mml:mrow><mml:mn>0.6</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mi>Se</mml:mi><mml:mrow><mml:mn>0.4</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>
 superconductors with controlled amounts of interstitial excess Fe

Sun, Yue; Pan, Yongqiang; Zhou, Nan; Xing, Xiangzhuo; Shi, Zhixiang; Wang, Jinhua; Zhu, Zengwei; Sugimoto, Akihiro; Ekino, Toshikazu; Tamegai, T.; Kitano, Haruhisa

doi:10.1103/physrevb.103.224506

Cited by 11 publications

(6 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 5 shows the f p -h plot over a temperature range of 9-13.5 K with H∥ c. Here f p is the normalized pinning force of F p , where F p = J c × H, f p = F p /F p-max and h = H/H c2 according to the original Dew-Hughes model. The H c2 is obtained by directly measuring the SC transition under a large field over 40 T [31]. Here, we observed a significant shift of f ppeak position with temperature.…”

Section: Non-scaling Behavior Of Fp Along C Axismentioning

confidence: 79%

Anisotropic critical current density and flux pinning mechanism of Fe 1+y Te_0.6Se_0.4 single crystals

Pan

Zhou

Lin

et al. 2021

Supercond. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

Fe 1 + y Te0.6Se0.4 has considerable application potential due to its large critical current density (J c) and high upper critical magnetic field ( H c2 ). However, the uncertainty of the anisotropy of J c and the unclear flux-pinning mechanism have limited the application of this material. In this study, the J c in three directions were obtained from magnetic hysteresis loop measurements. A large anisotropy of J c a b / J c c ∼ 10 was observed, and the origin of the anisotropy was discussed in details. Flux pinning force densities (F p) were obtained from J c, and a non-scaling behavior was found in the normalized pinning force f p [ F p / F p-max ] versus the normalized field h[H/ H c2 ]. The peaks of pinning force shift from a high h to a low h with increasing temperature. Based on the vortex dynamics analysis, the peak shift was found to originate from the magnetization relaxation. The J c and F p at critical states free from the magnetic relaxation were regained. According to the Dew-Hughes model, the dominant pinning type in Fe 1 + y Te0.6Se0.4 clean single crystals was confirmed to be normal point pinning.

show abstract

Section: Non-scaling Behavior Of Fp Along C Axismentioning

confidence: 79%

Anisotropic critical current density and flux pinning mechanism of Fe 1+y Te_0.6Se_0.4 single crystals

Pan

Zhou

Lin

et al. 2021

Supercond. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…While for the Fe 0.73 Se 0.33 Te 0.67 film, the rather low Fe content causes large amount of Fe vacancies, which leads to the shrink of c-axis [14]. Some studies have directly observed excess Fe existing as single Fe atoms randomly located at the interstitial sites between the (Se, Te) layers [33,34]. By annealing the sample, the excess Fe atoms between the (Se, Te) layers can no longer be observed [33,34], accompanied by the reduction of Fe content to the stoichiometric value [34].…”

Section: Resultsmentioning

confidence: 99%

“…Some studies have directly observed excess Fe existing as single Fe atoms randomly located at the interstitial sites between the (Se, Te) layers [33,34]. By annealing the sample, the excess Fe atoms between the (Se, Te) layers can no longer be observed [33,34], accompanied by the reduction of Fe content to the stoichiometric value [34]. Therefore, we believe that when the Fe content is further reduced, there are no Fe atoms between the (Se, Te) layers that can be removed, so that Fe deficiency can only occur in the FeSeTe lattice, thus forming Fe vacancies.…”

Section: Resultsmentioning

confidence: 99%

“…In the whole phase diagram, the highest T c, onset is obtained at the Se content of around 0.8, which is consistent with previous phase diagram [8][9][10], and the corresponding optimal Fe content is around 1.1. In order to suppress the phase separation in Fe y Se x Te 1−x bulks or single crystals, the Se content is usually set in the range of 0.4-0.5 [28,34,50,51]. In this case, the low Fe content of around 0.8 is more conducive to obtaining high T c, onset of Fe y Se x Te 1−x superconductors.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Reassembled phase diagram for Fe_ySe_xTe_1−x superconducting films grown by pulsed laser deposition

Zhang,

He,

Xiao

et al. 2023

Supercond. Sci. Technol.

View full text Add to dashboard Cite

FeySexTe1−x targets with different Fe contents have been prepared by the solid state reaction method followed by the hot-pressed sintering, and corresponding single-phase FeySexTe1−x films with high quality have been deposited at different substrate temperatures by the pulsed laser deposition. The evolution of the structure, superconductivity and pinning mechanism of the FeySexTe1−x superconductors with the Fe content has been investigated in detail. It can be found that the excess Fe can form the residual Fe impurities scattered in the polycrystalline bulks when the Fe content in the nominal composition exceeds 1.36. More importantly, a reassembled phase diagram for FeySexTe1−x superconducting films based on the change of both Fe and Se contents is constructed for the first time. It can be clearly seen that both the Fe and Se contents can greatly affect the superconductivity of FeySexTe1−x films within a wide range of Fe content (0.67 ≤ y ≤ 1.48). The Fe vacancies caused by the Fe deficiency is beneficial to the improvement of both critical temperature and activation energy, while with the increase of the Fe content, the superconductivity degrades because of the introduction of the interstitial Fe and the planar defects. The optimal Fe content at constant Se content shifts to the higher value with the increase of Se content. Our results facilitate the rational regulation of the superconducting properties, as well as the study of the underlying superconducting mechanism of FeSeTe superconductors.

show abstract

“…[6][7][8] It is essential to synthesize high-quality FeSe1−𝑥Te𝑥 single crystals with bulk superconductivity for investigating the intrinsic physical properties. [9][10][11][12][13][14][15][16] The as-grown Fe 1+𝛿 Se1−𝑥Te𝑥 single crystals with the self-flux method inherently contains excess Fe atoms (𝛿 in quantity) for Te substitution 𝑥 > 0.5, which occupy the interstitial sites of the Fe(Se,Te) layers. [17] These interstitial irons are found to strongly suppress superconductivity and cause the physical properties to vary from sample to sample, [7,10,14,[18][19][20] interfering with a consistent understanding of the intrinsic physics.…”

mentioning

confidence: 99%

Hydrothermally Obtaining Superconductor Single Crystal of FeSe_0.2Te_0.8 without Interstitial Fe

Yan

Liu

et al. 2023

Chinese Phys. Lett.

View full text Add to dashboard Cite

Here we report a hydrothermal route to remove interstitial excess Fe in non-superconducting iron chalcogenide Fe1+δ Se1-x Te x single crystals. The extra-Fe-free FeSe0.2Te0.8 (δ ~ 0) single crystal thus obtained shows bulk superconductivity at T c ~ 13.8 K, which is about 2 K higher than the FeSe0.2Te0.8 sample obtained by usual postannealing process. The upper critical field μ 0 H c2 is estimated to be ~42.5 T, similar to the annealed FeSe0.2Te0.8. It is surprising to find that, the hydrothermal FeSe0.2Te0.8 exhibits a remarkably small isothermal magnetization hysteresis loop at T = 3 K. This yields an extremely low critical current density J c ~ 1.1×102 Acm-2 (over 100 times smaller than the annealed FeSe0.2Te0.8) and indicates more free vortices in the hydrothermal FeSe0.2Te0.8.

show abstract

Comparative study of superconducting and normal-state anisotropy in Fe1+yTe0.6Se0.4 superconductors with controlled amounts of interstitial excess Fe

Cited by 11 publications

References 67 publications

Anisotropic critical current density and flux pinning mechanism of Fe 1+y Te_0.6Se_0.4 single crystals

Anisotropic critical current density and flux pinning mechanism of Fe 1+y Te_0.6Se_0.4 single crystals

Reassembled phase diagram for Fe_ySe_xTe_1−x superconducting films grown by pulsed laser deposition

Hydrothermally Obtaining Superconductor Single Crystal of FeSe_0.2Te_0.8 without Interstitial Fe

Contact Info

Product

Resources

About

Comparative study of superconducting and normal-state anisotropy in Fe1+yTe0.6Se0.4 superconductors with controlled amounts of interstitial excess Fe

Cited by 11 publications

References 67 publications

Anisotropic critical current density and flux pinning mechanism of Fe 1+y Te0.6Se0.4 single crystals

Anisotropic critical current density and flux pinning mechanism of Fe 1+y Te0.6Se0.4 single crystals

Reassembled phase diagram for Fe y Se x Te1−x superconducting films grown by pulsed laser deposition

Hydrothermally Obtaining Superconductor Single Crystal of FeSe0.2Te0.8 without Interstitial Fe

Contact Info

Product

Resources

About

Anisotropic critical current density and flux pinning mechanism of Fe 1+y Te_0.6Se_0.4 single crystals

Anisotropic critical current density and flux pinning mechanism of Fe 1+y Te_0.6Se_0.4 single crystals

Reassembled phase diagram for Fe_ySe_xTe_1−x superconducting films grown by pulsed laser deposition

Hydrothermally Obtaining Superconductor Single Crystal of FeSe_0.2Te_0.8 without Interstitial Fe