Application of Direct Stress Using a Multilayered Actuator to tune Transport Properties of Manganites*

Substances that undergo a first order phase transition can show coexistence of two phases. The manganite compound La_0.33Pr_0.34Ca_0.33MnO₃ has a first order transition between a ferromagnetic metallic phase and a nonmagnetic insulating phase and at certain temperatures the two phases coexist. In this phase separated state, the compound is extremely sensitive to external perturbations such as strain. Here, we use a multilayered actuator (MLA) composed of Lead Zirconate Titanate (PZT) to apply direct stress to an La_0.33Pr_0.34Ca_0.33MnO₃ thin film and measure the effect of strain on electrical resistance. We obtained a strain of only ∼10^-6 . However, our experiments showed that even such a small strain is sufficient to induce a shift in the phase transition temperature of La_0.33Pr_0.34Ca_0.33MnO₃ making it a promising material for strain sensors.