Deformation and stress at pop-in of lithium niobate induced by nanoindentation

In this study, a novel approach of high speed scratching is carried out on silicon (Si) wafers at nanoscale depths of cut to investigate the fundamental mechanisms in wafering of solar cells. The scratching is conducted on a Si wafer of 150 mm diameter with an ultraprecision grinder at a speed of 8.4 to 15 m/s. Single-point diamonds of a tip radius of 174, 324, and 786 nm, respectively, are used in the study. The study finds that at the onset of chip formation, an amorphous layer is formed at the topmost of the residual scratch, followed by the pristine crystalline lattice beneath. This is different from the previous findings in low speed scratching and high speed grinding, in which there is an amorphous layer at the top and a damaged layer underneath. The final width and depth of the residual scratch at the onset of chip formation measured vary from 288 to 316 nm, and from 49 to 62 nm, respectively. High pressure phases are absent from the scratch at the onset of either chip or crack formation.

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“…For diamond tip, E i and v i are 1141 GPa and 0.07, respectively 28 . The total displacement h is consistent with Hertzian elastic contact 29 :…”

Section: Discussionsupporting

confidence: 58%

A novel approach of high speed scratching on silicon wafers at nanoscale depths of cut

Zhang

Guo

Wang

et al. 2015

Sci Rep

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142

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“…The reason for the suddenness of the event is that it typically relates to the homogeneous nucleation of dislocation loops followed by their rapid expansion and multiplication [14,15]. However, twinning is also known to proceed under falling stresses following nucleation [16] and so it too can be expected to create pop-in type phenomena [17].The occurrence of pop-ins is sensitive to surface preparation [18][19][20]. In the case of single crystals of pure Mo, pop-ins were present during indentation of electro-polished surfaces but not after polishing with 0.05 lm alumina slurry, due to the defects introduced [18].…”

mentioning

confidence: 99%

mentioning

confidence: 99%

Distinguishing between slip and twinning events during nanoindentation of magnesium alloy AZ31

2016

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“…Zhang et al [ 12 ] indicated that the (111) plane of Cd 0.9 Zn 0.1 Te was more fragile, and easily brought about serious microscratches by a nano-scratching test on CdZnTe crystals, while the shear bands appeared on the (111) of Cd 0.96 Zn 0.04 Te. Nano-indentation tests were conducted on LN crystals [ 13 ], focused on the pop-in phenomenon during loading, and the results showed various hardness on different planes. Although the nano-scratching and nano-indentation tests have been gradually adopted in material mechanical properties evaluation to guide the design of process parameters [ 14 , 15 , 16 ], the study on LN is still very rare, especially on the critical cutting depth along specific orientations.…”

Section: Introductionmentioning

confidence: 99%

Effect of the Anisotropy Mechanical Properties on LN Crystals Fixed-Abrasive Lapping

et al. 2020

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The anisotropy of lithium niobate (LN) single crystals in mechanical properties affects its material removal uniformity during lapping. The nano-indentation hardness (HI) and elastic modulus(E) of Z-cut wafer and X-cut wafer were measured by a nano-indentation tester. The nano-scratching tests were adopted to evaluate its critical cutting depth (dc) of brittle ductile transition along crucial orientations of Z-cut and X-cut, respectively. A series of fixed-abrasive lapping tests were carried out to explore the effect of anisotropy on the lapping process. The results indicated that the HI of Z-cut was slightly higher than that of X-cut, while the E of Z-cut was about 1.1 times of the latter. The dc value of each orientation varies greatly. The lapping tests showed that the material removal rate (MRR) of Z-cut was lower than that of X-cut, for its high HI and E. Meanwhile, the surface quality of Z-cut was better than that of X-cut, for the larger dc of Z-cut. The research of mechanical properties of LN has guiding significance for its lapping process.

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Deformation and stress at pop-in of lithium niobate induced by nanoindentation

Cited by 21 publications

References 28 publications

A novel approach of high speed scratching on silicon wafers at nanoscale depths of cut

A novel approach of high speed scratching on silicon wafers at nanoscale depths of cut

Distinguishing between slip and twinning events during nanoindentation of magnesium alloy AZ31

Effect of the Anisotropy Mechanical Properties on LN Crystals Fixed-Abrasive Lapping

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