X-ray Diffraction and Piezoelectric Studies during Tensile Stress on Epoxy/SbSI Nanocomposite

Abstract

In this paper, the performance of epoxy/SbSI nanocomposite under tensile stress was investigated. X-ray diffraction studies show the main stress mode has shear nature in the case of elastic deformation, while a combination of shear and tensile stress during plastic deformation caused lattice deformation of SbSI and shift of sulfur atoms along the c axis of the unit cell. Apart from that, the piezoelectric signals were recorded during tensile tests. Epoxy/SbSI nanocomposite responded to the applied tensile stress by generating a piezoelectric current with a relatively high value. The measured piezoelectric peak-to-peak current is relatively high (Ip-p = 1 pA) in comparison to the current flowing through the sample (8.16 pA) under an applied voltage of 100 V. The current level is independent of the deformation speed rate in contradistinction to complex stress states. The signal comes from the whole volume of the sample between electrodes and is generated by shear stress.

Design of piezoelectric nanogenerator based on BiFeO3/epoxy resin with potential application for wearable electronic devices

“…One can see that higher matrix elasticity results in clear peak shift under 20 MPa load, which contributes to a greater extent to plastic deformation of composite. Considering that typical operation conditions of PENG applied for wearable devices are in elastic deformation, [20][21][22]41,53 it should be noted that thermally treated composites might exhibit higher impact resistance, but in this case, stress transfer to BFO particles will be less effective.…”

“…The increase in compressive stress is a result of epoxy matrix shrinkage on BFO particles. 21 However, the temperature condition applied for thermally treated composites affects the compressive stress generated in BFO particles. Literature reports a positive effect of lattice distortion in BFO structure, resulting in an increase in residual stress, on its piezoelectric properties, 36,38,39 which can be similar to rare-earth doping of BFO structure.…”

“…Despite the fact, that the epoxy resin shows no piezoelectric properties, numerous studies can be found which showed the high applicability of such epoxy/piezoelectric systems. 21,22,[41][42][43] In a typical composite fabrication procedure, the proper weight amount of BFO particles was introduced into the epoxy matrix (mechanically mixed for 30 min, followed by 30 min of ultrasonic mixing), then the mixture was degassed and mixed with a curing agent in a proper weight ratio (100:23). After degassing under vacuum, samples were cast into silicon molds (30 mm radius and 4 mm thick).…”

“…8,9 These mentioned material properties result in many literature reports on 0-3 composites dedicated to piezoelectric applications. 5,[7][8][9][17][18][19][20][21][22] Among most important piezoelectric materials for 0-3 composites, the following should be mentioned: perovskite-type oxides as PbZr x Ti 1-x O 3 17 and BaTiO 3, 18-20 but also halcohalides as SbSI 21,22 and hexagonal ZnO. 23,24 One of the many noteworthy and well-known multiferroic materials, exhibiting both ferroelectricity and antiferromagnetic properties above room temperature, 4,25,26 with high potential application in various fields of electronics is BiFeO 3 (BFO).…”

“…This solution allows to reduce the amount of piezoelectric material and leads to simplify fabrication and processing with simultaneous improvement in elasticity of the final PENG device 8,9 . These mentioned material properties result in many literature reports on 0‐3 composites dedicated to piezoelectric applications 5,7–9,17–22 . Among most important piezoelectric materials for 0‐3 composites, the following should be mentioned: perovskite‐type oxides as PbZr x Ti 1‐x O 3 17 and BaTiO 3, 18–20 but also halcohalides as SbSI 21,22 and hexagonal ZnO 23,24 …”