龐磁阻 ( Colssal magnetoresistance, CMR ) 材料因在外加磁場下，電阻值變化的特性使得他在許多磁性材料中脫穎而出，在研究上具有豐富的潛力，至今仍為熱門的研究對象。獨立自支撐技術 ( Freestanding, FS ) 這項技術可以使二維材料脫離原本磊晶基板，使材料在應用以及開發上更加靈活。從先前的研究中發現，鑭鈣錳氧 ( La1-xCaxMnO3, LCMO ) 薄膜的磁阻 ( Magnetoresistance, MR ) 效應會受到基板對薄膜造成的應力影響產生變化，薄膜的厚度則會影響相變溫度。結合應力的影響以及FS，本實驗提供了一個方法，藉由FS先將特定厚度的LCMO薄膜取下並轉移至鋁酸鑭 ( LaAlO3, LAO ) 基板，並在此之上進行薄膜磊晶，便能得到兩種受不同應力影響的LCMO薄膜組合，並對這種側向磊晶的結構進行電性的量測。經過量測後我們發現，LCMO的磁阻最高可到-340%，而且樣品出現了兩個相變點。磁阻的提升與相變點的增加有助於拓展這個材料的應用空間。我們的實驗結果提供了一個未來研究LCMO及龐磁阻的新方向。

Lanthanum manganite (La1-xCaxMnO3, LCMO) has attracted much attention due to its strongly correlated systems with strong interplays among charge, spin, orbital, and lattice degrees of freedom, such as colossal magnetoresistance (CMR). From the previous researches, it is believed that lattice parameters of LCMO and CMR properties can be influenced by substrate-induced strains. In this work, we demonstrate a way to combine two different strained LCMO via Freestanding (FS) technique. The resistance-temperature (R-T) curve exhibits two different transition points, and the highest Magnetoresistance (MR) is -340%. Our result provides a new pathway to study in the CMR and LCMO.

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