摘要

近年鐵基超導體：鐵硒、鐵硒碲和鉀鐵硒相繼被發現超導特性，經比較其超導相變溫度和晶格結構分析後，普遍認為鐵硒層狀結構的距離和其超導相變溫度成正相關關係。「氨熱法」是一種將金屬溶解於液態氨當中，讓金屬原子嵌入鐵硒的層狀結構之間的方法。實驗結果經氨熱法反應後的樣本晶格長度明顯增長，甚至超過原本預期的長度，且超導相變溫度也確實大幅增加。這是因為在氨熱法的過程中，除了原本預期的金屬原子外，連氨分子也一起嵌入了結構之內。

在本篇文章裡，由於鐵硒碲是在做氨熱法須預備的重要材料，我們首先探討鐵硒碲的超導特性品質與其成分的關係，從中我們學到了一些關於鐵硒碲的合成特性以及與超導品質的關係。

鍶嵌入鐵硒層的實驗非常成功，我們找到了其超導特性並探討了相關的磁性和結構。

在鹼金嵌入鐵硒碲層方面的實驗就沒那麼順利，我們發現了一些奇特的磁性現象，文章中將介紹我們觀察到的現象，包含磁性和結構部份。

Abstract

Iron-based superconductor KFe2Se2 (122-structure) was been reported soon after the discovery of FeSe and FeSe1-xTex (11 structure) system. From the results of lattice structure and critical temperature of the system, enlargement of the distance between FeSe layers is believed positive to enhance Tc. Ammothermal method, by dissolving metallic atoms in liquid ammonia, is reported a way to intercalate them into FeSe layers. The greatly enhanced the size of lattices and Tc after the intercalation was achieved, and not only metallic atoms but also ammonia molecular is intercalated into the structure.

In this article, we first surveyed the quality of superconductivity with different ratio FeSe1-xTex., which is the most important material of intercalation. Some facts of compounding FeSe1-xTex samples are learned

Strontium is successfully intercalated in FeSe layers by the method, the superconductive and magnetic properties and also the lattices structure are measured and calculated. .

The experiments of alkaline earth metal intercalating into FeSe1-xTex.is also applied. But the result is not as expected and with uncertain problems. Strange magnetic behaviors and structures are discussed

Key Words: , , , .

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