Chemical vapor deposition of ordered structures in YAG–alumina eutectic system

The eutectic structure of metals and ceramics is the result of a self-organization phenomenon in which multiple solid phases solidify with an ordered structure from a liquid phase. Hence, a melt-solidification process was the only way to generate ordered structures in a ceramic eutectic system. Here, we prepared ordered structures of Y₃Al₅O₁₂ (YAG)–Al₂O₃ composites via chemical vapor deposition in the YAG–Al₂O₃ eutectic system. Spatially periodic YAG rod and lamellar structures were generated in an alumina matrix homoepitaxially grown on the sapphire substrates on the Al₂O₃-rich side of the eutectic composition, whereas α-Al₂O₃ rod and lamellar structures were generated in a YAG matrix on the Y₂O₃-rich side. The results reveal that the pattern formation of ordered structures in a ceramic eutectic system can occur not only during in the melt-solidification process but also during the vapor deposition process. The Ce³⁺-doped YAG–Al₂O₃ composite film converts some of the blue light into yellow light, allowing some of it to pass through, and emitting white light. The Eu³⁺-doped YAG–Al₂O₃ composite film can be utilized as a scintillation screen for a high-resolution X-ray imaging test to see though a semiconductor storage device.     

Map building using helmet-mounted LiDAR for micro-mobility

Artificial Life and Robotics - This paper presents a point-cloud mapping method using a light detection and ranging (LiDAR) mounted on a helmet worn by a rider of micro-mobility. The distortion in...