Epitaxial growth and electrical properties of {\it perovskite} HoMnO$_{3}$ thin films

Recently, it was predicted that orthorhombic HoMnO$_{3}$ would exhibit relatively large polarization (of the order of $\mu$C/cm$^ {2}$) due to the existence of a ferroelectric order in the {\it E}- type magnetic structure [1]. We have fabricated perovskite HoMnO$_{3}$ thin films on SrTiO$_{3}$ (001) substrates by pulsed laser deposition. X-ray 2$\theta$-$\theta$ scan shows (00 {\it l}) peaks only indicating that there are no secondary phases. The reciprocal space mapping around the SrTiO$_{3}$ (103) Bragg reflection and the $\phi$ scan of the HoMnO$_{3}$ (103) peak reveals the tetragonal symmetry of the films and the epitaxial relationship, [100]HoMnO$_{3}$ // [100]SrTiO$_{3}$ and [001] HoMnO$_{3}$ // [001]SrTiO$_{3}$, confirming that the film has the perovskite structure and not the hexagonal one. The films show good insulating properties at low temperatures. We will present electrical properties of the films including results of PUND measurements in applied magnetic field below the Neel temperature. This work is supported by NSF MRSEC, ARO, and the W. M. Keck Foundation. \newline [1] Sergienko et al., PRL 97, 227204 (2006).