水热辅助烧结氢氧化钙溅射靶材：通往量子级CaO薄膜的途径
Hydrothermally-Assisted Sintering of Calcium Hydroxide Sputtering Targets: A Route to Quantum-Grade CaO Thin Films
AI总结：
通过水热辅助烧结（冷烧结）制备高致密氢氧化钙陶瓷靶材，用于沉积高质量CaO薄膜，实现(002)取向外延生长。
摘要：
在本报告中，我们展示了通过水热辅助烧结（通常称为冷烧结）制备的致密多晶氢氧化钙陶瓷，用于生产高纯度氢氧化钙靶材，以沉积氧化钙薄膜。氢氧化钙陶瓷在100°C至300°C的温度下，施加400 MPa的单轴压力烧结1小时，无需热脱水即可达到高达98%的理论密度。在所有温度下，氢氧化钙靶材中均保留了水镁石相。氢氧化钙前驱体粉末和最终靶材中都存在少量等量的碳酸钙，表明在形成和致密化过程中产生的额外碳酸钙极少。通过扫描电子显微镜记录了致密化过程中的微观结构演变，表明存在质量传输和塑性变形两种致密化机制。将水热辅助烧结工艺放大，生产出适用于溅射沉积的2英寸直径氢氧化钙靶材。我们还报道了从这些靶材在r面蓝宝石衬底上沉积外延氧化钙薄膜。实现了(002)取向的外延薄膜，沉积速率为1.2 nm/min且随时间稳定。我们注意到，即使向溅射过程中添加1 mol%的氧气，在此速率下生长过程中的高能轰击也可能相当显著，因此需要低沉积速率条件。
英文摘要：
In this report we demonstrate dense polycrystalline calcium hydroxide ceramics fabricated by hydrothermally-assisted sintering - often referred to as cold-sintering - to produce high-purity calcium hydroxide targets for calcium oxide thin film deposition. Calcium hydroxide ceramics exhibit up to 98% theoretical density without thermal dehydration, when sintered at temperatures between 100 °C - 300° C with 400 MPa applied uniaxial pressure for 1 hour. The brucite phase is preserved in calcium hydroxide targets at all temperatures. Small equivalent fractions of calcium carbonate are present in both the calcium hydroxide precursor powder and final targets suggesting minimal additional production during formation and densification. Microstructure evolution during densification is documented by scanning electron microscopy, indicating both mass transport and plastic deformation densification mechanisms. The hydrothermal-assisted sintering process is scaled up to produce 2-inch diameter calcium hydroxide targets suitable for sputter deposition. We also report epitaxial calcium oxide film deposition from these targets on r-plane sapphire substrates. (002) oriented epitaxial films are achieved with a time-stable 1.2 nm per minute deposition rate. We note that energetic bombardment during growth can be substantial at these rates even when 1 mol% oxygen is added to the sputtering process necessitating the low deposition rate conditions.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
