Stacking faults and polymorphs in alumina nanorods

Abstract We investigated the stacking faults in γ-alumina nanorods by means of high-resolution electron microscopy. Our results show that the ordered arrangement of stacking faults in γ-alumina led to the transformation of γ- to δ-alumina. We suggest that the alternative arrangement of (010) and (010) stacking faults induces the transformation. This model is in agreement with our experimental results and consistent with other investigations. Our work sheds some light on the long-disputed transition mechanism in metastable alumina polymorphs. Acknowledgments We gratefully acknowledge financial support from the National Natural Science Foundation of China under Grants No. 50332020 and No.50171070, and the Science and Technology Commission of Shenyang. We also acknowledge support from the National Outstanding Young Scientist Foundation for X.L. Ma with Grant No. 50325101 and the Special Funds For the Major State Basic Research Project of China (Grant No. 2002CB613503).