Shape Memory Oxide

Smart materials remember their original shape on removal of external parameters (like temperature, electric field, magnetic field, etc.), and are said to exhibit the shape memory effect. Our work is mainly focused on converse piezoelectric ceramics that show the remnant strain, and an electric field in opposite polarity is required to get initial state. The maximum remnant strain is observed at the morphotropic phase boundary (MPB) composition in these ceramics, which makes them useful for various applications such as actuators, memory, and transducer devices. In this regard, we perform a detailed study on lead-based as well as lead-free oxides (in bulk and thin-film form) with modification at A-site and B-site (i.e., by composition variation) to achieve shape memory behaviour. Here, we achieved a 0.27 % remnant strain in bulk PZST based compound at MPB composition.

Figure 1. For MPB composition in modified PZST system, (a) P–E hysteresis loop and (b) Field-induced strain loop.