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磁阻效應

磁阻效應. 磁阻  (H) 是被定義為樣品在磁場中電阻之改變量，即  (H) =  (H) -  (H = 0) ，此處  (H) 是在磁場 H 下樣品之電阻率。. 材料有不同之磁阻 , 其原因可來自 ; 電荷受羅倫茲力之作用而改變甚行進路徑造成電荷與晶格間散射機率增加 , 此時  (H) > 0 ; 受磁矩在磁場下電子自旋與磁矩間間散射狀態改變的影響 , 若樣品是鐵磁性材料 , 其磁矩對電荷自旋之散射機率會因為外加磁場之增加而減小 , 此時  (H) < 0 。 其他物理原因。. Z. Z. X. H. X. Y. Y.

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磁阻效應

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  1. 磁阻效應 磁阻(H) 是被定義為樣品在磁場中電阻之改變量，即(H) = (H) - (H = 0)，此處(H) 是在磁場H下樣品之電阻率。 • 材料有不同之磁阻,其原因可來自; • 電荷受羅倫茲力之作用而改變甚行進路徑造成電荷與晶格間散射機率增加, 此時(H) > 0 ; • 受磁矩在磁場下電子自旋與磁矩間間散射狀態改變的影響, 若樣品是鐵磁性材料, 其磁矩對電荷自旋之散射機率會因為外加磁場之增加而減小, 此時(H) < 0 。 • 其他物理原因。

  2. Z Z X H X Y Y A A B H B J J (a) (b) 樣品置於外加磁場H 之中, 若將電流 J 通於樣品, 此樣品在磁場下產生磁阻效應。(a)為縱向磁阻效應 (H 之方向平行於J之方向);(b)為橫向磁阻效應(H之方向垂直於J之方向)

  3. a (5.47 Å) Mn O Nd,Sr c (7.7 Å) b (5.46 Å) 氧化物 Nd1-XSrXMnO3巨磁阻材料中Nd, Sr, Mn 和O原子之排列情形，此化合物之居禮溫度約在 230 K。

  4. NSMO and LCMO films show the Curie temperature at 222 K and 250 K respectively.

  5. V = V3-V2→Resistance Vh = V2-V1→Hall coefficient ● The pattern for resistivity and Hall measurements

  6. (b) Temperature dependence of the longitudinal resistivity xx for YBa2Cu3Oy (YBCO) (1500 Å and NSMO (2100 Å) films.

  7. YBa2Cu3Oy/PrBa2Cu3Oy Temperature dependence of the longitudinal resistivity for YBCO/PBCO superlattices in fields parallel to (a) the c-axis and (b) the ab-plane.

  8. T* Resistivities of YBa2Cu3Oy/La0.7Ca0.3MnOy (YBCO/LCMO) superlattice, showing a zero magnetoresistance at T*.

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