Ferroelectric microdomains and magnetocapacitance in Ti-doped YMnO3

We have investigated microstructure giving rise to the magnetocapacitance (MC) in Ti-doped YMn$_{1-x}$Ti$_{x}$O$_{3}$ by electron microscopy, combining with conventional magnetic measurement We found characteristic diffuse scatterings elongated along both the [001] and [110] directions in x=0.175, which shows the maximum value of the MC. In addition, the microdomains with the size of 10-20nm consisting of ferroelectric (FE) phase appear in x=0.175. As the Ti concentration (x) is increasing, the paraelectric phase grows up at the expense of the FE phase and the paraelectric phase is dominated above x=0.2. We will discuss the relation between the MC and FE microdomains in this compound.