本實驗主要研究La1.85Sr0.15CuO4化合物中不同金屬對Cu之取代效應。我
們摻雜過渡元素Zn、Ni、Ag溶質於La1.85Sr0.15CuO4樣品中，並觀察其晶
格結構,電阻率,磁化率,顯微結構及載子濃度等各種物理性質的變化。由
粉末x光繞射儀量測結果可知：當Zn、Ni摻雜值x≦0.075時，樣品仍維持
La1.85Sr0.15CuO4 tetragonal 結構，只是晶格常數會稍有變化。至於摻
雜Ag的樣品，當摻雜值x＞0.1時，樣品不是單相，而是具有La2O3、Ag 測
結果可知：不論是摻雜磁性元素(Ni)、非磁性元素(Zn) 都會破壞La-Sr-
Cu-O的超導性，其中摻雜Zn對超導破壞性 怌z。此原因可由顯微結構實驗
中半定量分析的結果得知，由於Ag很難進入 LaSrCuOuO超導性受Ag的影響
很小。接著本實驗介紹TC 降低的各種可能原因，其中更解釋 Zn 對超導
破壞性最強的原因是感應磁矩較 Ni 大，造成 Magnetic pair-
breaking 較強。

This experiment studies mainly the effect of dopping different
metals which displace Cu in LaSrCuO system. We dop Zn, Ni, Ag
in LaSrCuO system and observe the changes of lattice structure,
the ratio of electric resistance, magnetic susceptibility,
structure and carrier concentration. With result of x-ray
powder diffraction, we know when the dopping value of Zn, Ni is
smaller than 7%, the sample still has tetragonal structure, but
the lattice constants have some changes. For the sample dopped
by Ag, we know when the dopping value of Ag is larger than 10%,
sample not single phase, which appears La2O3 and Ag phases. In
the magnetic measurment, we know Ni, Zn and Ag will destroy the
susperconductivity of LaSrCuO system. In the experiment of
microscopic structure,we conclude that Ag can't exist in the
lattice of LaSrCuO system. Most Ag concentrates as Ag cluster
in few grains, so Ag has smaller influence in the
superconductivity of the LaSrCuO system than Zn, Ni. Finally,
we introduce the reasons of dopping Zn, Ni and Ag destroy the
superconductivity of LaSrCuO system.
This experiment studies mainly the effect of dopping different