Crystal Preferred Orientation of Heteroatomic Co/ZnO/Co₃ZnC Nanoclusters for Balanced Conductive and Polarization Loss

Comprehensively understanding the interdependency between crystal plane orientation and intrinsic electromagnetic (EM) properties in heteroatomic metal-nanoclusters (HACs) advances high-performance electromagnetic wave (EMW) absorbers. Here, a new surface charge deposition and high-temperature pyrolysis strategy is proposed to prepare HAC with crystal Preferred orientation for elucidating the EMW loss mechanisms. The deposition and diffusion rate of atoms on the surface of cubic ZIF-8 crystal seeds is regulated by using cetyltrimethylammonium bromide (CTAB) as a physical barrier, then the pyrolysis process gives rise to Co/ZnO/Co₃ZnC HAC with crystal plane orientation. The results show that the Co₃ZnC plays a dominant role in governing the EMW loss, along the (110) plane orientation attenuates EMW through conductive loss, while along the (200) plane orientation increases the HAC-c polarization losses, optimizes impedance matching, and balances conductive loss with polarization loss. The HAC-c (CTAB) exhibits an ultrahigh effective absorbing bandwidth (EAB) of 7.12 GHz (with a matched thickness of 2.3 mm). Furthermore, compared to non-oriented HAC-s (sodium dodecyl sulfate) and HAC-p (polyvinyl pyrrolidone), the EMW absorption performance of the HAC-c is significantly improved. This study clarifies the relationship between crystal plane orientation and the mechanism of EMW attenuation, proposing a new approach for designing high-performance EMW absorption materials.