Progress towards an electron electric dipole moment search in Europium-Barium Titanates

We report on recent progress towards an electron electric dipole moment (EDM) search using mixed Europium Barium Titanates. In particular, we have synthesized and characterized Eu$_{0.5}$Ba$_{0.5}$TiO$_3$ ceramics and identified them as a good candidate for a solid state electron EDM search. These samples are ferroelectric below $200\mbox{ K}$ and paramagnetic above $1.8\mbox{ K}$. Because of the spontaneous electric polarization in these ceramics, the seven unpaired $4f$ electrons of the Eu$^{2+}$ ions in the lattice feel a large effective electric field, on the order of $10\mbox{ MV/cm}$. The estimated sensitivity due to this large electric field and large densities ($n\approx 10^{22}$~cm$^{-3}$) is approximately $d_e\sim10^{-28}e\mbox{cm}$ after ten days of averaging.