Thermal-induced irreversible straining of ultrathin boron nitride nanosheets
Abstract
We investigate the thermal-induced mechanical deformations in mono- and few-layer hexagonal boron nitride nanosheets (BNNSs) on flat silicon dioxide substrates by using atomic force microscopy and Raman spectroscopy techniques. The measurements reveal that the deformation of thin BNNS follows the reversible expansion/contraction of the substrate at relatively low temperatures. Irreversible deformations in BNNS are observed at elevated temperatures, which are attributed to interfacial sliding on the BNNS-substrate interface that is caused by the temperature-dependent thermal expansion mismatch of BN and substrate materials. Monolayer BNNS is found to possess the highest onset temperature of irreversible straining, which decreases with an increase in the BNNS thickness. The interfacial load transfer characteristics of the BNNS-substrate interface are quantitatively investigated using a micromechanics model. The analysis reveals that monolayer BNNS possesses a maximum interfacial shear strength of about 28.38 MPa on its binding interface with substrates at about 525 °C. The findings are useful to better understand the fundamental structural and mechanical properties of BNNS and in pursuit of its applications, in particular, those involved with high temperature processing and/or working environments.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Feb 04, 2019
- Source ID
- 10.1063/1.5083960
Entities
People
- Changhong Ke
- Feilin Gou
- Wenyang Qu
Organizations
- Air Force Office of Scientific Research
- Binghamton University
- Division of Civil, Mechanical & Manufacturing Innovation