Simple 4-segment thermal cycling pyroelectric measurement protocol for differentiating between ferroelectric and non-ferroelectric materials

Abstract

The rare-earth chromates, RECrO3 and manganites REMnO3 (RE = Eu, Y, Dy, Ho, Gd) are considered potential room temperature multiferroics. However, artefacts and undesirable signals pose a severe challenge in confirming the ferroelectric (FE) phase, especially in pyroelectric current measurement technique. We propose a simple modified approach to the technique, named as 4-segment thermal cycling protocol. This protocol assists in isolating the irreversible thermally stimulated current from those associated with spontaneous and reversible nature of the electric polarization in FE phase. Here, we have compared simulated response of two hypothetical materials; an FE material and a paraelectric material. Further, we experimentally verify the protocol in a single crystal of prototype FE material, Glycine Phosphite. Using the proposed protocol, we investigated polycrystalline materials, HoCrO3 (reported multiferroic earlier) and DyFe0.5Mn0.5O3. Our results expound on the absence of reversible spontaneous electric polarization in temperature ranges tested.