Berkovich indentation-induced deformation behaviors of GaN thin films observed using cathodoluminescence and cross-sectional transmission electron microscopy

Jian, Sheng-Rui

doi:10.1016/j.apsusc.2008.04.078

Cited by 31 publications

(36 citation statements)

References 22 publications

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“…The listed values of H are consistent with those reported by Jian et al 33 We found that the strain hardening of GaN, partially induced from the penetration depth, had increased slightly. In addition, we attribute the hysteresis loops as arising from the volume change upon the reverse phase transformation of the GaN films, resulting either in a pop-out (or a kink back) or in a slope change (elbow) of the unloading part of the load-displacement curve.…”

Section: Resultssupporting

confidence: 94%

Effect of cyclic indentation on epitaxial GaN films

Tsai

Yau

2012

Surface Engineering

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This paper describes the mechanisms of Berkovich nanoindentation induced mechanical deformation of GaN films under various loading-reloading cycles, analysed using cathodoluminescence, atomic force microscopy (AFM) and SEM. The AFM and SEM studies revealed that bursts, due to the nucleation of dislocations, occurred after nine loading-reloading cycles; these bursts resulted in incipient slip bands and/or the to and fro motion of mobile dislocations under the stress field. Cathodoluminescence analysis indicated the generation of individual dislocations and residual deformation on the GaN film; the decrease in hardness H can be used to determine the material properties of films undergoing repeated loading-reloading cycles.

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Section: Resultssupporting

confidence: 94%

Effect of cyclic indentation on epitaxial GaN films

Tsai

Yau

2012

Surface Engineering

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“…The curve appears to be smooth and regular. The absence of any discontinuities along either the loading or unloading segment is in sharp contrast to those observed in GaN thin films [21,22] and in single-crystal Si [23,24], indicating that neither twinning nor pressure-induced phase transformation is involved here.…”

Section: Resultsmentioning

confidence: 73%

Structural and nanomechanical properties of BiFeO3 thin films deposited by radio frequency magnetron sputtering

et al. 2013

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The nanomechanical properties of BiFeO3 (BFO) thin films are subjected to nanoindentation evaluation. BFO thin films are grown on the Pt/Ti/SiO2/Si substrates by using radio frequency magnetron sputtering with various deposition temperatures. The structure was analyzed by X-ray diffraction, and the results confirmed the presence of BFO phases. Atomic force microscopy revealed that the average film surface roughness increased with increasing of the deposition temperature. A Berkovich nanoindenter operated with the continuous contact stiffness measurement option indicated that the hardness decreases from 10.6 to 6.8 GPa for films deposited at 350°C and 450°C, respectively. In contrast, Young's modulus for the former is 170.8 GPa as compared to a value of 131.4 GPa for the latter. The relationship between the hardness and film grain size appears to follow closely with the Hall–Petch equation.

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“…It clearly shows that multiple pop-ins (discontinuities) in load-displacement curve occur during loading and reflects the process of plastic deformation in the material. The phenomena are usually attributed to dislocation nucleation and propagation during loading as have been observed in a wide variety of materials [14,17], or micro-cracking [18] event. This observation is in contrast to that reported in the previous studies of InP [12,19], where only single "pop-in" event was observed.…”

Section: Resultsmentioning

confidence: 99%