Link of Weak Ferromagnetism to Emergence of Topological Vortices in Bulk Ceramics of h-LuMnxO3 Manganite

Abstract

Research on topological defects in hexagonal manganites exposed uncovered properties of topologically protected domains and domain walls. Topological defects of h-REMnO3 oxides (RE = Lu–Dy and Sc, In) modify essential multiferroic properties. Despite wide research with single crystals of stoichiometric composition, for the case of polycrystalline ceramics rare studies explored the effects of adjustment in chemical composition on phase transition temperatures, antiferromagnetic ordering, topological domain sizes, and potential modifications of the vortex density predicted by the Kibble–Zurek mechanism (KZM). The effect of cation vacancy doping of either Mn, or Lu sublattices of h-LuMnxO3, on appearance of ferroelectric vortices at the Curie point of apolar-to-polar ferroelectric ordering, TC, in bulk ceramics is investigated here. For cooling rates up to 40 K min–1 the Kibble–Zurek mechanism sets the density of FE vortices in ceramics of the LuMnxO3 system. Magnetic hysteresis loops taken from the represen...