Unique coexistence of incommensurate and commensurate magnetic order in TbMnO3 strained films

Abstract

Neutron diffraction studies on epitaxially strained orthorhombic (010) oriented TbMnO 3 thin films verify a theoretical prediction of an unusual magnetic phase with coexisting incommensurate and a commensurate order. Magnetic field dependent measurements of the (0 q 1) and (0 1 + q 1) Bragg reflections confirm that the magnetic intensity corresponding to an incommensurate q value has contributions from magnetic domains with both incommensurate and commensurate order. The ratio between the population of domains with commensurate and incommensurate order can be tuned by the magnetic field. In addition, the incommensurate order shows strong evidence of supporting the predicted ab cycloidal spin structure.

Role of Dy on the magnetic properties of orthorhombic DyFeO3

“…Such modulation has also been reported for other orthoferrites [45,46]. In orthomanganates, a splitting of a commensurate peak has also been reported in highly strained films, where a spin spiral coexists with an E -type ordering [47]. It should be noted also that the atomic positions for Dy are identical to the structural positions at higher temperature and do not show a shift as would be expected when an internal magnetic field gives rise to ferroelectricity.…”

Multiple magnetic ordering phenomena in multiferroic o−HoMnO3

“…This rules out a bc cycloid as the main Mn AF motif (as in the case of TbMnO 3 ), but could agree with an ab cycloid (as in the case of DyMnO 3 ) or a modulated E-type (as suggested in Refs. [21,19,25]). The order induced below T N by the Mn on the paramagnetic Ho moments therefore contains only moment components along the c axis [19].…”