Measurements on magnetoelectrics under extreme conditions.

Abstract

This work investigates the properties of a potential magnetoelectric multiferroic EuTiO3.

The interest in this material is due to it’s unusual low temperature properties. A quantum

paraelectric and an antiferromagnet, it exhibits a small anomaly in the dielectric

constant and magnetisation simultaneously below the N´eel temperature. It is suspected

that the small anomaly is the signature of a transition to a ferroelectric state. In this

work, the specific heat data was analysed and it was found that there is no thermodynamic

phase transition below the N´eel temperature. The magnetisation data confirmed

that the unusual anisotropy found previously was due to a misalignment of the crystal

axes. A system to measure the dielectric constant in the PPMS using the three terminal

technique was built and was tested using a reference sample of SrTiO3.