Surface chemical disorder and lattice strain of GaN implanted by 3-MeV Fe10+ ions

Chemical disorder on the surface and lattice strain in GaN implanted by Fe¹⁰⁺ ions are investigated. In this study, 3-MeV Fe¹⁰⁺ ions fluence ranges from 1×10¹³ ions/cm² to 5×10¹⁵ ions/cm² at room temperature. X-ray photoelectron spectroscopy, high-resolution x-ray diffraction, and high-resolution transmission electron microscopy were used to characterize lattice disorder. The transition of Ga-N bonds to oxynitride bonding is caused by ion sputtering. The change of tensile strain out-of-plane with fluence was measured. Lattice disorder due to the formation of stacking faults prefers to occur on the basal plane.     

单纯正交表OA$_\lambda(3, 5, v)$的存在性

An orthogonal array of strength t,degree k,order v and index λ,denoted by OAλ(t,k,v),is a λvt× k array on a v symbol set such that each λvt× t subarray contains each t-tuple exactly λ times.An OAλ(t,k,v) is called simple and denoted by SOAλ(t,k,v)if it contains no repeated rows.In this paper,it is proved that the necessary conditions for the existence of an SOAλ(3,5,v) with λ≥ 2 are also sufficient with possible exceptions where v = 6 and λ∈ {3,7,11,13,15,17,19,21,23,25,29,33}.