Template-Guided Nitridation of Epitaxial Cr Thin Films into Oriented CrN

Transition-metal nitrides have attracted broad interest because of their diverse mechanical, electronic, and magnetic functionalities. Here, we present a template-guided nitridation approach for synthesizing oriented nitride thin films, demonstrated using the epitaxial Cr-to-nitride transformation. For epitaxial Cr (110) films, nitrogen plasma treatment followed by thermal annealing produces Cr2N (0002) and CrN (111), depending on the annealing temperature, while NH3 nitridation at 800 °C yields CrN (111) with well-defined in-plane ordering. By contrast, amorphous Cr films remain amorphous after nitridation. The oriented nitride formation in epitaxial films originates from the crystallographic compatibility among the close-packed or pseudoclose-packed planes of Cr (110), Cr2N (0002), and CrN (111). These results highlight template-guided nitridation as a promising strategy for synthesizing oriented transition-metal nitrides for advanced coatings and functional device applications.