Buckling and Ferromagnetism of Aligned Cr-Doped ZnO Nanorods

Aligned Cr-doped ZnO nanorods have been successfully fabricated at 600 °C by in situ doping of Cr into ZnO nanorods using a vapor transport approach. Comprehensive structural analyses indicate that dopant Cr occupies Zn sites in ZnO and nanorods align along the [0001] direction. Photoluminescence spectra reveal unusual features peaked at 401 and 488 nm, respectively. Magnetic measurements have shown that nanorod arrays exhibit ferromagnetism at 10 and 293 K, which is likely due to defect-mediated exchange interactions. Nanomechanical studies have revealed a critical buckling load of 517 μN and a buckling energy of ca. 4.2 × 10−11 J, respectively, for the Cr-doped ZnO nanorod arrays.