HRTEM image and EDX analysis. (a) HRTEM image of Gd2O3-NC memories with nanostructure tunneling layer. The marks No. 1 and No. 2 indicate the X-ray spot locations of the EDX analysis. (b) EDX analysis of locations No. 1 and No. 2 in the HRTEM image. Inset is the Hf/Al ratio of the two locations. The Gd2O3-NC embedded in a-Gd2O3 is observed in the HRTEM. The interfacial layer SiO2 is also observed between Al2O3 and Si.