Nanomechanical properties of a Ni nanodot-patterned surface

Abstract

Nanomechanical properties of a Ni nanodot-patterned surface (NDPS) on a Si substrate were investigated using nanoindentation. The Ni NDPS was fabricated by thermal evaporation of Ni through a porous anodized aluminum oxide template onto a Si substrate. Plan-view transmission electron microscopy and nanobeam diffraction were used to characterize the Ni nanodot crystal structure. Scanning electron microscopy and atomic force microscopy were used to characterize the morphology and deformation of the Ni nanodots before and after nanoindentation. The elastic modulus and hardness of the Ni nanodots were found to be 159 ± 22 and 7.7 ± 1.0 GPa, respectively. The critical shear stress for initiating plastic deformation in the Ni nanodot was estimated to be 8.3 ± 1.0 GPa, which is close to the theoretical shear strength of 7.6 GPa in dislocation-free single crystal Ni.

Nanoindentation modeling of a nanodot-patterned surface on a deformable substrate

“…Our study of the mechanical properties of a Ni NDPS showed that the hardness of Ni nanodots on the NDPS is very close to the hardness of nanocrystalline Ni and is much higher than the hardness of microcrystalline and bulk Ni (Wang et al, 2008). The Ni NDPS also showed significant adhesion and friction reduction for potential tribological applications in MEMS (Zou et al, 2006).…”

“…The material properties used in this study are listed in Table 1. The elastic modulus and yield strength used for Ni were obtained from a previous experimental study of the mechanical properties of a Ni NDPS (Wang et al, 2008). The yield strength of a Ni nanodot was taken as one third of the hardness, which is 2.57 GPa.…”

“…AFM line cuts alone are not sufficient, because the AFM tip radius of curvature is about 10 nm, which is not much smaller than the radius of curvature of the nanodot. The procedure was described in detail elsewhere (Wang et al, 2008). It was found that the nanodots are of conical-shape with a spherical apex.…”

“…The contact load-deformation behavior of NDPSs must be fully understood. Modeling of the contact between an indenter tip and a NDPS will shed light on the contact behavior of NDPSs observed in micro-/nano-scale friction and adhesion experiments, since they often involve indenting or sliding a spherical indenter tip on the NDPSs (for example, Burton and Bhushan, 2005;Yoon et al, 2006;Wang et al, 2008;Zou et al, 2006). This paper presents a numerical simulation of nanoindentation of a Ni NDPS on a deformable Si substrate using spherical diamond tips with different tip radii.…”

Fabrication of Ordered Gold Nano Dot Array by Nano Plastic Forming and Self-Assembly

“…(11), (12) , ポーラスアルミ ナテンプレートを用いた方法 (13), (14) などが提案されている. これらの方法では, 多数のナノドットを短時間に作製 することが可能であり, 極めて微細なナノドットを得ることができる.…”