本研究利用固態合成法製備鉭酸鹽類螢光體主體晶格材料，分別將三價稀土金屬離子(Re3+= Eu3+, Tb3+, Dy3+, Sm3+, Er3+, Tm3+, Bi3+)等作為發光中心，並利用X光粉末繞射、掃描式電子顯微鏡、熱重分析與差分式掃描熱分析、紫外-可見光全反射光譜與光激發光光譜儀進行其結構與發光特性鑑定。探討Mg2LaTaO6和Ca2LaTaO6主體晶格結構與活化劑濃度如何影響發光特性。
發射紅光之Eu3+所摻雜不同主體螢光體中，激發光譜並無太大變化；而摻Eu3+螢光體放射光譜顯示Eu3+離子均佔據由5D0→7F2電偶極躍遷主導的非反轉對稱格位，Ca2LaTaO6: Eu3+的發射光譜，Eu3+離子5D1 、5D2與5D3高能階躍遷放光能被偵測；在900 ~ 1450℃之間，Ca2LaTaO6: Eu3+的發光強度會隨著煆燒溫度上昇而提高；以Eu3+離子活化之強紅光新穎鉭酸鹽之鎂/鈣離子共摻發光可調變螢光粉，探討陽離子分別由鹼土金屬(Mg、Ca)組成其晶格場改變之影響，取Mg2LaTaO6:Eu3+最佳放射強度之添加濃度30mol%Eu，由放射光譜可知，Mg0.6Ca1.4LaTaO6:Eu3+為最佳化組成，其呈現最強的紅光放射。此外，當鎂/鈣莫耳比例為1：3時，Mg0.5Ca1.5LaTaO6:Eu3+為最佳化組成螢光粉色座標為(0.66, 0.34)。
發射綠光之Tb3+摻雜的螢光體，高濃度Tb3+摻雜時，發光光譜間並無太大差異，而在低濃度Tb3+摻雜Mg2LaTaO6主體晶格時，發光光譜無Tb3+離子中5D3 高能階躍遷；而Ca2LaTaO6：Tb3+的色度座標可以從藍綠光偏移至綠光。
近白光Dy3+離子、橘紅光Sm3+離子、藍光Tm3+離子、綠光Er3+與Bi3+離子，透過Mg2LaTaO6和Ca2LaTaO6兩個不同主體晶格結構，對照吸收光譜、激發光譜、發射光譜和衰減時間的差異性，觀察金屬離子與氧配位場特性、共價鍵結強弱和占據位置對稱性等，就稀土離子為活化劑所形成的發光中心，因為稀土離子6s5p外殼層的屏蔽作用，使得4f電子的躍遷不受結晶場的影響，因此大部分三價稀土離子摻雜的螢光體，其放射光譜基本上與自由態的稀土離子相同。

The objet of this study is to search new oxide based phosphors. The M2La1-xRexTaO6 (M =Mg, Ca; Re = Eu3+, Tb3+, Dy3+, Sm3+, Er3+, Tm3+, Bi3+ ) phosphors are synthesized by solid-state reaction process and then calcined at 1450℃for 8 h, the absorption and emission behaviors under excitation source around near-UV region were examined. By using Thermal Analysis, XRD, SEM, TEM and PL spectra, the characterization and photo-luminescent properties of prepared phosphors were well investigated.
The characteristics of Mg2LaTaO6: Eu3+ and Ca2LaTaO6: Eu3+ phosphors were found to be dependent on the amounts of europium ions. The calcined powders emit bright red luminescence centered due to 5D0→7F2 electric dipole transition. The maximum PL intensity has been obtained for 30mol% concentration of Eu3+ in Mg2LaTaO6 and Ca2LaTaO6. In addition, PL intensity of the Ca2LaTaO6: Eu3+ increased with the formation temperature from 900 to 1450 ℃.
By controlling the molar ratios of Mg / Ca and amount of Eu3+ ions, it can improve the photoluminescence properties of red emission phosphors. The intensity of 5D0→7F2 transition reaches a maximum when the relative ratio of Mg / Ca is 3:7. The CIE chromaticity coordinates were found to be (0.66, 0.34) for Mg0.5Ca1.5LaTaO6:Eu3+.
No blue emission would be observed in Mg2LaTaO6: Tb3+ even at very low Tb3+ concentration. The blue emission due to relaxation from the 5D3 level is absent. Furthermore, rare earth Dy3+ (close to white emission), Sm3+ (reddish-orange emission)、Tm3+ (blue emission), Er3+ and Bi3+ (green emission) doped Mg(or Ca)2LaTaO6 materials are promising phosphor candidates. The influences of host lattice of Mg2LaTaO6 and Ca2LaTaO6 on spectroscopy of luminescent materials were the factors of crystal field, covalency effect and crystal structure. However, since rare- earth (RE) ions have numbers of efficient and narrow emission lines in the visible region, the position of which is insensitive to their matrices due to the shielding effect of outer 5s and 5p electrons.

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