Cr、Nb、Mo和W的摻雜對(Bi, La)4Ti3O12、(Bi, Nd)4Ti3O12和(Bi, Pr)4Ti3O12膜的微結構及鐵電性的影響

Effects of Cr-, Nb-, Mo- and W-doping on the Microstructures and Ferroelectric Properties of (Bi, La)4Ti3O12, (Bi, Nd)4Ti3O12 and (Bi, Pr)4Ti3O12 Films

張天麟(T.L. Chang) ； 柯志遠(C.Y. Ko) ； 林文台(W.T. Lin)

《材料科學與工程》 38卷1期 (2006/03) Pp. 39-43

https://doi.org/10.6409/JMSE.200603.0039

摘要

利用化學溶液鍍著法生長Bi3.5Nd0.5Ti3O12 (BNT)及Bi3.25La0.75Ti3O12 (BLT)，探討摻雜Cr及Nb對其微結構及鐵電性質的影響。在摻雜Cr的BNT (BNTCx)及BLT (BLTCx)中，以Cr(上標 3+)的形式取代Ti(上標 4+)的位置會減少殘餘極化值(2Pr)，此外會使得晶粒大小減小，促進C軸成長傾向，及增加氧空缺。摻雜Nb在BNTNx和BLTNx薄膜中，是以Nb(上標 5+)取代Ti(上標 4+)，當x=0.005，2Pr值會增加到43μC/平方公分和35μC/平方公分，然後再隨著Nb添加量的增加而減少。Bi3.55Pr0.48Ti3O12先退火625℃後鍍上電極再退火到750℃的兩階段退火製程，和鍍完上電極再退火750℃的製程相比，薄膜有較大2Pr值。原因是其Pt上電極與薄膜間的介面反應前者較後者輕微。在Mo摻雜BPT(BPTMx)和W摻雜(BPTWx)薄膜中，x=0.01時有最大2Pr，31μC/平方公分和35μC/平方公分，當x大於0.03時2Pr則會下降。

關鍵字

BiNdTiO ； BiLaTiO ； BiPrTiO膜 ； 離子摻雜 ； 鐵電性

並列摘要

Effects of Cr-, Mo-, W-, and Nb-doping and annealing processing on the microstructures and ferroelectric properties of chemical-solution-deposited Bi3.5Nd0.5Ti3O12 (BNT) and Bi3.25La0.75Ti3O12 (BLT) films and sputtered Bi3.55Pr0.48Ti3O12 (BPT) films were studied. For Cr-doped BNT and BLT films Cr(superscript 3+) replacing Ti(superscript 4+) can reduce remnant polarization (2Pr) because of the reduction of the grain size, the enhancement of c-axis oriented growth, and the increase of oxygen vacancies. For Nb-doped BNT (BNTNx) and BLT (BLTNx) films Nb(superscript 5+) replacing Ti(superscript 4+) can increase the 2Pr up to 43 and 35μC/cm^2 at x=0.005 and then decrease the 2Pr for x larger than 0.03, respectively. For BPT films the two-step annealing, i.e., first annealed at 625℃ before deposition of upper Pt electrodes and then annealed at 750℃ after deposition, can significantly improve the ferroelectric properties as compared with the one-step annealing, i.e., only annealed at 750℃. The reason can be attributed to the less interface reactions between the film and Pt electrodes for the two-step annealing than for the one-step annealing. For Mo- and W-doped BPT films (BPTMx and BPTWx) the 2Pr increases up to 31 and 35μC/cm^2 at x=0.01 and then decreases for x larger than 0.03, respectively.

並列關鍵字

Lanthanide-modified Bi4Ti3O12 films ； cation doping ； ferroelectric properties