在Mg0.06Fe1-xCoxTe0.55Se0.45中參雜Co對超導的影響

Effect of Co-doping on Tc of Mg0.06Fe1-xCoxTe0.55Se0.45 Superconductors

黃柏勛(Bo-Syun Huang)

指導教授 ： 李文新

國立中正大學/理學院/物理學系/碩士(2016年)

摘要

本論文主要是研究一系列Mg0.06Fe1-xCoxTe0.55Se0.45(0≦x≦0.05)的晶體結構以及用Co取代Fe對超導和磁性的變化。我們以0.01的比例間格，製作了六個樣品。經由X-ray粉末繞射圖得知這些樣品雖非100%純相，但也都接近tetragonal單相，其space group為 P4/nmm。磁性量測的結果顯示，在x = 0、0.01、0.02、0.03、0.04有超導反磁訊號，磁性量測的Tc,onset 分別等於12.5K、10.5K、9.5 K、8.5 K、4 K。說明了此鐵基超導系統只要以少量( >4%)之Co取代Fe，即可將此鐵基超導性質完全破壞。此結果亦說明了鐵在此晶體結構系統中鐵離子之有序性與其超導性有很大之關係。另外，本超導系統之低臨界磁場HC1也很小，HC1 ~ 4 Oe。

關鍵字: 超導

關鍵字

超導

並列摘要

This thesis is to study a series of Mg0.06Fe1-xCoxTe0.55Se0.45 (0 ≦ x ≦ 0.05) crystal structure and Co-substituted Fe with changes in superconductivity and magnetism. Our ratio of 0.01 between the grid, made six samples. We informed via X-ray powder diffraction pattern of these samples, though not 100% pure phase, but also close to tetragonal single-phase, its space group is P4 / nmm. The results of magnetic measurements show, in x = 0,0.01,0.02,0.03,0.04 superconducting diamagnetic signal, the magnetic measurement of Tc, onset equal to 12.5K, 10.5K, 9.5 K, 8.5 K, 4 K. Description of the iron-based superconducting system as long as a small amount (> 4%) of the Co-substituted Fe, this iron-based superconducting properties can be completely destroyed. This result also shows the crystal structure of iron in this orderly system of iron and its superconductivity of a great relationship. In addition, the lower critical magnetic field of the superconducting system of the HC1 is small, HC1 ~ 4 Oe.

Key word: Superconductors

並列關鍵字

Superconductors

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