Sara J. Callori | Searcharxiv

arXiv2025

Observation of Dual Spin Reorientation Transitions in Polycrystalline CeCr$_x$Fe$_{1-x}$O$_3$(x=0.33 and 0.67)

We investigate the magnetic behavior of polycrystalline CeCr$_x$Fe$_{1-x}$O$_3$ (x = 0, 0.33, 0.67, and 1) synthesized via solid state reaction. Rare earth orthoferrite and orthochromite materials are well known for exhibiting spin reorientation transitions. Cr$^{3+}$ doping in CeFeO$_3$ results in the unusual occurrence of two spin reorientation transitions, $Γ_4$(G$_x$, A$_y$, F$_z$) $\rightarrow$ $Γ_1$(A$_x$, G$_y$, C$_z$) near 230 K and $Γ_4$(G$_x$, A$_y$, F$_z$) $\rightarrow$ $Γ_2$(F$_x$, C$_y$, G$_z$) near 100 K. In addition, two Néel transitions are identified. The results indicate that CeCr$_x$Fe$_{1-x}$O$_3$ offers a rich collection of magnetic behaviors with application potential for spintronic devices.

cond-mat.mtrl-sci↗

arXiv2015

In-situ x-ray diffraction and the evolution of polarization during the growth of ferroelectric superlattices

In epitaxially strained ferroelectric thin films and superlattices, the ferroelectric transition temperature can lie above the growth temperature. Ferroelectric polarization and domains should then evolve during the growth of a sample, and electrostatic boundary conditions may play an important role. In this work, ferroelectric domains, surface termination, average lattice parameter and bilayer thickness are simultaneously monitored using in-situ synchrotron x-ray diffraction during the growth of BaTiO$_3$/SrTiO$_3$ superlattices on SrTiO$_3$ substrates by off-axis RF magnetron sputtering. The technique used allows for scan times substantially faster than the growth of a single layer of material. Effects of electric boundary conditions are investigated by growing the same superlattice alternatively on SrTiO$_3$ substrates and 20nm SrRuO$_3$ thin films on SrTiO$_3$ substrates. These experiments provide important insights into the formation and evolution of ferroelectric domains when the sample is ferroelectric during the growth process.

cond-mat.mtrl-sci↗