Determination of the Mechanical Properties of PIN–PMN–PT Bulk Single Crystals by Nanoindentation

Abstract

The present study aimed to experimentally evaluate the mechanical properties of Pb(In1/2Nb1/2)O3−Pb(Mg1/3Nb2/3)O3−PbTiO3 (PIN−PMN−PT) bulk single crystals with different crystallographic directions using the nanoindentation technique. The load−indentation depth curves, elastic and plastic deformations, hardnesses, and Young’s moduli of [100]- and [110]-oriented 0.28PIN−0.43PMN−0.29PT bulk single crystals were investigated. Our results show that with an increase in the maximum indentation depth hmax, the plastic residual percentage increased for both the [100]- and the [110]-oriented single crystals. At each hmax, the plastic residual percentage of the [100]-oriented PIN−PMN−PT single crystals was less than that of the [110]-oriented PIN−PMN−PT single crystals. At hmax from 500 nm to 2000 nm, the plastic deformation was larger than the elastic deformation, and the plastic residual percentage was larger than 50% for both the [100]- and the [110]-oriented single crystals. This means that the plastic deformation dominated in the indentation process of PIN−PMN−PT single crystals. The indentation size effect on the hardness of the PIN−PMN−PT single crystals was apparent in the nanoindentation process. Both the hardness and the Young’s modulus of the [100]-PIN−PMN−PT single crystals were greater than those of the [110]-PIN−PMN−PT single crystals, which indicates that the PIN−PMN−PT single crystals had anisotropic mechanical characteristics.

Keywords

• relaxor-based ferroelectric pin–pmn–pt single crystal
• nanoindentation
• load–depth curves
• elastic and plastic deformation
• hardness
• young’s modulus