Spindle-Shaped Apatite La–Silicate Mesocrystals Grown via a Multistep Nucleation and Growth Mechanism, A New Strategy for Preparing Ordered Nanoscale Superstructures

A precise control over the growth of mesocrystals composed of crystallographically aligned nanocrystals is necessary to exploit their collective properties for potential applications. Here, we describe a successful preparation of spindle-shaped apatite La–silicate (ap-LSO) mesocrystals with an ordered arrangement of elongated nanocrystals along <i>c</i>-axis through a solvothermal process, as revealed by X-ray diffraction, scanning electron microscopy, transmission electron microscopy–selected area electron diffraction, and high-resolution transmission electron microscopy. It has been shown that a multistep nucleation and growth mechanism would be responsible for the formation of the mesocrystals. This novel mesocrystal formation mechanism breaks through the classical crystallization norm and opens a new way to constructing mesocrystals with nanoscale superstructures