Noncentrosymmetric commensurate magnetic ordering of multiferroic ErMn₂O₅

Abstract

Abstract. The non-centrosymmetric magnetic structure of ErMn 2 O 5 has been shown to be very similar to that of HoMn 2 O 5 (Vecchini et al., 2008 Phys. Rev. B 77 134434). The magnetic modulation at 25 K has propagation vector k=(1/2,0,1/4) and the symmetry imposes very few constraints on the magnetic configurations allowed. Only by combining the results of bulk magnetisation measurements, powder and single crystal neutron diffraction and spherical neutron polarization analysis was it possible to distinguish clearly between different models. The susceptibility measurements show that the erbium magnetic moments are aligned parallel to the c-axis indicating strong single-ion anisotropy. Spherical neutron polarimetry demonstrates the presence of two unequally populated chirality domains in ErMn 2 O 5 single crystals. X-ray diffraction measurements on an ErMn 2 O 5 powder using synchrotron radiation show that the buckling angles of the Mn-O-Mn bond change below the transition to the ferroelectric phase.

Magnetic order of multiferroicErMn2O5studied by resonant soft x-ray Bragg diffraction

“…Interesting is the presence of a ferroelectric polarization in the commensurate phase. The magnetic order has been studied in detail with neutron [9][10][11][12][13][14] and resonant x-ray diffraction. [15][16][17][18] The order parameters and the magnetic phase diagram have also recently been investigated by theory including symmetry considerations.…”

4f spin driven ferroelectric-ferromagnetic multiferroicity in PrMn2O5 under a magnetic field

“…The first magnetic transition around 40 ± 5 K to an incommensurate antiferromagnetic (AF) state is followed by a second transition, leading to a commensurate AF ordering of the Mn spins. An electric polarization P emerges with either the first (R = Tb, Sm, Nd) or the second magnetic transition along the b axis, asserting the type-II character of the multiferroicity [11][12][13][14][15][16][17][18][19][20]. The associated strong coupling has been reported for GdMn 2 O 5 and TbMn 2 O 5 , for which the electric polarization P can even be reversed by applying a modest magnetic field of a few teslas [1,2,21,22].…”

A facile and environmentally friendly route to multiferroic nanorods and their size-dependent magnetic properties

“…It is noteworthy that the synthesis of RMn 2 O 5 particles noted above requires a high temperature solid-state process, which leads to the aggregation of particles. Among RMn 2 O 5 , ErMn 2 O 5 multiferroics possess a noncentrosymmetric magnetic structure 19 and a large magnetic susceptibility. Hydrothermal synthesis stands out as an effective method among other various strategies to produce nanomaterials due to its advantageous simple and low-temperature processing characteristics.…”

“…More importantly, the fundamental understanding of the structureproperty relationship in RMn 2 O 5 is still critically lacking. Among RMn 2 O 5 , ErMn 2 O 5 multiferroics possess a noncentrosymmetric magnetic structure 19 and a large magnetic susceptibility. 20 To date, very few efforts have been made in synthesizing morphologically controlled 1D ErMn 2 O 5 nanostructures.…”