 This study proposes a novel approach to reduce the size of metal organic frameworks, MOFs. The researchers used a spatial confined growth technique to encase small size MOFs derivatives within hollow carbon nano cages. They found that this process resulted in a significant reduction in the size of the MOFs crystal, which in turn affected its dielectric properties. Specifically, they observed that the dielectric polarization was enhanced by the presence of the hollow cavity, resulting in improved microwave attenuation. Additionally, the researchers were able to visualize the effects of the phase hybridization on the dielectric polarization using electron holography. These findings provide insight into how size dependent oxidation can be used to control the phase hybridization of MOFs derivatives, leading to optimized microwave attenuation. This article was authored by Han Xiaosu, Guo Zhengzheng, Yi Wang, and others.