Gadolinium Oxide Nanoring and Nanoplate:  Anisotropic Shape Control

Colloidal cubic Gd 2 O 3 nanorings and nanoplates are selectively prepared from low-temperature (90 °C) hydrolysis of Gd(acac) 3 and subsequent in situ thermal dehydration of the hydrolyzed precursor−surfactant aggregates at 320 °C. Notably, the final morphologies of Gd 2 O 3 are directly transferred from the shapes of hydrolyzed precursors. Further ring size control could be accomplished using surfactants with different lengths, and importantly, the reported method could be extended to other metals such as Er and Yb.