摘要
Ni self-assembly has been performed on Ga N(0001), Si(111) and sapphire(0001) substrates. Scanning electron microscopy(SEM) images verify that the Si(111) substrate leads to failure of the Ni assembly due to Si–N interlayer formation; the GaN(0001) and sapphire(0001) substrates promote assembly of the Ni particles. This indicates that the GaN/sapphire(0001) substrates are fit for Ni self-assembly. For the Ni assembly process on Ga N/sapphire(0001) substrates,three differences are observed from the x-ray diffraction(XRD) patterns:(i) Ni self-assembly on the sapphire(0001) needs a 900?C annealing temperature, lower than that on the GaN(0001) at 1000?C, and loses the Ni network structure stage;(ii) the Ni particle shape is spherical for the sapphire(0001) substrate, and truncated-cone for the GaN(0001) substrate; and(iii) a Ni–N interlayer forms between the Ni particles and the GaN(0001) substrate, but an interlayer does not appear for the sapphire(0001) substrate. All these differences are attributed to the interaction between the Ni and the Ga N/sapphire(0001) substrates. A model is introduced to explain this mechanism.
Ni self-assembly has been performed on Ga N(0001), Si(111) and sapphire(0001) substrates. Scanning electron microscopy(SEM) images verify that the Si(111) substrate leads to failure of the Ni assembly due to Si–N interlayer formation; the GaN(0001) and sapphire(0001) substrates promote assembly of the Ni particles. This indicates that the GaN/sapphire(0001) substrates are fit for Ni self-assembly. For the Ni assembly process on Ga N/sapphire(0001) substrates,three differences are observed from the x-ray diffraction(XRD) patterns:(i) Ni self-assembly on the sapphire(0001) needs a 900?C annealing temperature, lower than that on the GaN(0001) at 1000?C, and loses the Ni network structure stage;(ii) the Ni particle shape is spherical for the sapphire(0001) substrate, and truncated-cone for the GaN(0001) substrate; and(iii) a Ni–N interlayer forms between the Ni particles and the GaN(0001) substrate, but an interlayer does not appear for the sapphire(0001) substrate. All these differences are attributed to the interaction between the Ni and the Ga N/sapphire(0001) substrates. A model is introduced to explain this mechanism.
基金
Project supported by the National Natural Science Foundation of China(Grant Nos.61473266 and 61673404)
the Program for Science&Technology Innovation Talents in Universities of Henan Province,China(Grant No.16HASTIT033)
the Science and Technique Foundation of Henan Province,China(Grant Nos.132102210521,152102210153,182102210516,and 172102210601)
the Key Program in Universities of Henan Province,China(Grant No.17B520044)
the Science and Technique Project of the China National Textile and Apparel Council(Grant No.2018104)
