本研究利用固態反應法製備矽摻雜鍺酸鑭基磷灰石電解質材料，藉由添加不同量的 Si4+ 取代鍺酸鑭基磷灰石中四面體的 Ge4+ 位置，試圖以固態反應法合成純相的 La10Ge6-xSixO27 (x=0、1.2、2.4、3.6、4.8、6)，並針對以固態反應法合成純相的 La9.5Ge6-xSixO26.25 系統 (x= 0、0.6、1.2、1.8、2.4、3.6、4.8、6)，觀察其晶體結構的變化與導電性質間的關聯性。
實驗結果顯示合成 La10Ge6-xSixO27 系統時，由 x=0 的 X 光繞射圖譜，存在許多雜相，繞射峰寬化，推測其結構接近六方晶系；而 x=6 存在未反應完全的 La2O3 與 La2SiO5 二次相，故利用固態反應法難以合成純相。
合成 La9.5Ge6-xSixO26.25 系統的結果顯示，當矽的添加量達到 x = 3.6 時，已出現明顯二次相 La2SiO5 的生成，故 La9.5Ge6-xSixO26.25 的固溶範圍約為 2.4，且其合成單一相的煅燒溫度也隨著 Si 含量而增加。並選擇具純相的 La9.5Ge6-xSixO26.25 (x=0、0.6、1.2、1.8、2.4) 粉末以 Rietveld 方法模擬精算晶格常數，觀察於固溶極限內，矽的添加會使鍺氧四面體產生改變而影響周遭晶體結構。以燒結後相對密度達 95% 以上之試片，得到在 x = 1.8 時具有較高導電率 0.0335 S/cm (800℃)，且其晶體結構中具有最大的 O3-O4 距離 3.3430Å 與 最大的 O3-La2 (長邊) 的距離 3.4725 Å，又進一步推測其間隙氧移動的範圍為位於 O3-La2 (長邊) 的範圍，並沿著 c 軸做螺旋路徑的遷移。

A series of silicon doped Lanthanum-Germanates apatite-type materials, La10Ge6-xSixO27 (x=0, 1.2, 2.4, 3.6, 4.8, 6) were prepared in an attempt to synthesize a single phase by solid-state method. Moreover, in order to observe the relationship between changes in the crystal structure and electrical conductivity when Si4+ with different content were doped into the Ge4+ sites of tetrahedra, single phase La9.5Ge6-xSixO26.25 (x= 0, 0.6, 1.2, 1.8, 2.4, 3.6, 4.8, 6) series were prepared using the solid-state method.
In the La10Ge6-xSixO27 series, the XRD pattern results indicated that lots of second phases existed and that the diffraction peak broadened when x=0; non-reacted La2O3 and second phase La2SiO5 existed when x=6. Thus, it’s difficult to synthesize a single phase using athe solid-state method.
In the La9.5Ge6-xSixO26.25 series, the XRD pattern results indicated that second phase La2SiO5 existed when x=3.6. Therefore, the solid solubility limit is about x =2.4, and the single phase calcination temperature increases as Si4+ content increases. Subsequently, five single phase powder samples, La9.5Ge6-xSixO26.25 (x=0, 0.6, 1.2, 1.8, 2.4) were selected to calculate lattice parameters using the Rietveld method as well as to analyze changes in the crystal structure; and the same five over-95% relative density bulks were selected to measure electrical conductivity. The results indicated that x=1.8 exhibited the highest conductivity at 800℃ (0.0335 S/cm), and that in the crystal structure analysis, x=1.8 had longest O3-O4 distance (3.3430Å) and the longest O3-La2 (longer) distance (3.4725Å). This indicated that x=1.8 had more space to allow oxygen ion for migration. Furthermore, the exsiting interstitial oxygen regions were around the O3-La2 (longer) space, and exhibited a sinusoidal-like path along the c-axis.

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