Single crystals of CaWO₄, also known as Scheelite, are grown by the Czochralski method in an atmosphere with 1 % oxygen in argon using a pure rhodium crucible. Since they are used as detector crystals in the CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) experiment, they need to have a high transparency and extremely low radioactive background. The two crystals which exhibit a somewhat gray color are as grown, the clear crystal in the middle underwent an annealing process in pure oxygen to eliminate the oxygen deficiency which is present for as grown crystals. The image is provided through the courtesy of Prof. Andreas Erb.

中文翻译：

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白钨矿晶体：（晶体研究和技术2/2020）

通过Czochralski方法，在纯氩气中，在含1％氧气的氩气中，通过Czochralski方法生长CaWO _4的单晶，也称为白钨矿。由于它们在CRESST（超导温度计的低温稀有事件搜索）实验中用作检测器晶体，因此它们需要具有高透明度和极低的放射性本底。呈现出略带灰色的两个晶体在生长时，中间的透明晶体在纯氧中进行退火处理，以消除在生长的晶体中存在的缺氧现象。图片由Andreas Erb教授提供。