Spin-lattice coupling and frustrated magnetism in Fe-doped hexagonal LuMnO ₃

Abstract

Strong spin-lattice coupling and prominent frustration effects observed in the 50% Fe-doped frustrated hexagonal (h)LuMnO3 are reported. A Néel transition at TN ≈ 112 K and a possible spin re-orientation transition at TSR ≈ 55 K are observed in the magnetization data. From neutron powder diffraction data, the nuclear structure at and below 300 K was refined in polar P 63cm space group. While the magnetic structure of LuMnO3 belongs to the Γ4 (P 6 3 c m) representation, that of LuFe0.5Mn0.5O3 belongs to Γ1 (P 63cm) which is supported by the strong intensity for the (100) reflection and also judging by the presence of spin-lattice coupling. The refined atomic positions for Lu and Mn/Fe indicate significant atomic displacements at TN and TSR which confirms strong spin-lattice coupling. Our results complement the discovery of room temperature multiferroicity in thin films of hLuFeO3 and would give impetus to study LuFe1−xMnxO3 systems as potential multiferroics where electric polarization is linked to giant atomic displacements.

Magnetic structures and magnetoelastic coupling of Fe-doped hexagonal manganitesLuMn1−xFexO3Fu1, Nair2, Xiao3 et al. 2016Phys. Rev. BSelf Cite200121View full textAdd to dashboardCite

“…A single phase of solid solution has been achieved in the half doped LuMn 0.5 Fe 0.5 O 3 [2,23]. Indeed the T N (~ 110 K) of LuMn 0.5 Fe 0.5 O 3 is higher than that of LuMnO 3 by about 20 K. The magnetic ground state of LuMn 0.5 Fe 0.5 O 3 has been described by a single magnetic representation Γ 1 or Γ 3 [2,23].…”

“…The possible coupling between magnetism and ferroelectricity in multiferroics has drawn extensive attention because of the potential technological significance in controlling one order parameter through the other. The hexagonal (h-) manganites RMnO 3 (R = rare earth) are an interesting group of multiferroics which exhibit a rich variety of physical phenomena [2,3]. Although the ferroelectric transition temperature (T F ~1000 K) of h-RMnO 3 is much higher than its antiferromagnetic (AFM) transition temperature (T N ~100 K) [3], evidence for coupling between magnetic and electric dipole moments has been revealed by means of dielectric constant measurements and high-resolution neutron diffraction [4,5].…”

“…A single phase of solid solution has been achieved in the half doped LuMn 0.5 Fe 0.5 O 3 [2,23]. Indeed the T N (~ 110 K) of LuMn 0.5 Fe 0.5 O 3 is higher than that of LuMnO 3 by about 20 K. The magnetic ground state of LuMn 0.5 Fe 0.5 O 3 has been described by a single magnetic representation Γ 1 or Γ 3 [2,23]. The crystal and magnetic structures of the Fe-rich compounds, LuMn 1-x Fe x O 3 (x ≥ 0.5), have been investigated using powder diffraction and inelastic neutron scattering in Ref.…”

Interplay of Magnetic Properties and Doping in Epitaxial Films of h‐REFeO3 Multiferroic Oxides

“…Addition of Mn to LFO system enlarges the a-lattice constant (5.992 Å), which in turn increases the lattice mismatch of the film and substrate (4.749 Å for ALO, and 5.160 Å for YSZ). [9,28] As it was previously reported, Mn doping shifts the spin reorientation temperature (T R ) from the one observed in Sc-doped LuFeO 3 single crystals. [9,28] T R values in single crystals of LFO doped with Mn increase from 55 to 107 K as Mn doping decreases from 40% to 33%.…”

“…[9,28] As it was previously reported, Mn doping shifts the spin reorientation temperature (T R ) from the one observed in Sc-doped LuFeO 3 single crystals. [9,28] T R values in single crystals of LFO doped with Mn increase from 55 to 107 K as Mn doping decreases from 40% to 33%. [9,29] Figure 3c,d gives the magnetic susceptibility of LFMO films grown on YSZ and ALO substrates, respectively.…”