鎦釩氧單晶之光學與物理性質研究

Abstract

1996年，單晶LuVO4第一次以Czochralski法被製作出來。因為其在可見光靠近紅外光區域具有高穿透率，LuVO4成為相當吸引人的偏光材料。然而在文獻中對於單晶鎦釩氧的研究，至今仍多著重在光學的部分。 我們使用保加利亞法製作LuVO4，所得單晶大小約為1x0.5x0.05cm3。透過單晶X光繞射證實樣品為化學劑量比正確且純度高的單晶LuVO4，接著本論文在光學方面做了拉曼光譜儀和橢圓儀的測量；在物理特性方面，除了XRD結構探討之外，我們亦進行了X光吸收光譜量測，以確認相關元素的價態，並透過掃描式電子顯微鏡中之能量發散光譜，進一步分析其元素組成；在磁性方面我們透過了超導量子干涉儀，研究不同溫度下磁化率的變化；電性方面我們利用LCR meter測量了電容和介電損耗在不同溫度下的變化。經由上述實驗，我們得到對LuVO4單晶更完整的拉曼光譜圖和雙折射率圖，並發現此單晶不具磁性，且由a軸所量測的介電常數相當穩定。

LuVO4 was firstly grown by Czochralski method in 1996 and was expected to be an attractive polarizer material owing to its high transmittance from VIS to NIR. However, the study of the single crystal LuVO4, has been mostly focused on the optical parts. In this thesis, we want to know more about this crystal by doing all kinds of experiments. We used the Bulgaria method to grow the single crystal with the dimension of 1x0.5x0.05cm3. At first, we used the single crystal XRD to confirm we got the high quality and the correct structure. Then we did many kinds of experiments. In the optical part, we measured the Raman spectrum and the ellipsometer. In the physical part, we measured the XRD, XAS, and the EDS. In the magnetic part, we used the SQUID to measure the M-T in different temperature. In the electric part, we used the LCR meter to measure the relative permittivity and dielectric loss. In conclusion, we got the more complete Raman spectrum, and the Birefringence picture. The crystal has no magnetism and the relative permittivity is quite stable.