Formation of Crystalline SrAl2O4 Nanotubes by a Roll-Up and Post-Annealing Approach

摘要

Soon after the identification of carbon nanotubes,[1] it wasdemonstrated that many layered inorganic compounds could be prepared in tubular morphologies.[2] The formation of inorganic nanotubes was suggested to occur by a curving and seaming process. Later, artificial lamellar structures were prepared in solution, from which nanotubes (or nanoscrolls) could be formed after heat treatment.[3] The thermally driven roll-up of thin layers into scrolls as a result of lattice expansion mismatch was also reported.[4] Such a process occurs when a two-layer thin film of Si/SiGe is heated: the film rolls up to form nanoscrolls, owing to the asymmetric strain on its two sides.