Novel multiferroic state and ME enhancement by breaking the AFM frustration in LuMn1−xO3. Issue 2 (14th December 2016)

• Record Type: Journal Article
• Authors: Figueiras, F. G.; Karpinsky, D.; Tavares, P. B.; Gonçalves, J. N.; Yañez-Vilar, S.; Moreira Dos Santos, A. F.; Franz, A.; Tovar, M.; Agostinho Moreira, J.; Amaral, V. S.
• Is Part Of: Physical chemistry chemical physics. Volume 19:Issue 2(2017)
• Page Start: 1335
• Page End: 1341
• Publication Date: 2016-12-14
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c6cp07682c
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Controlled off-stoichiometry in LuMn0.98 O3 preserves P 63 cm symmetry while exhibits a relevant ferromagnetic component for T < 92 K and an additional basal electric polarization not found in the utter LuMnO3 . Abstract : This study provides a comprehensive insight into the effects of controlled off-stoichiometry on the structural and multiferroic properties of the hexagonal manganite LuMn1− x O3+ δ ( x = 0.02; δ ∼ 0), supported by neutron powder diffraction measurements confirming single phase P 63 cm symmetry and evidencing a relevant ferromagnetic component, below T N ∼ 90 K, which breaks the archetypal geometrically frustrated antiferromagnetic state typically ascribed to LuMnO3 . The perturbations in the triangular disposition of spins prompt an additional electric polarization contribution and a clear enhancement of the magnetoelectric coupling which are in good agreement with the results of first principles calculations. In addition, Raman spectroscopy, dielectric permittivity, pyroelectric current and magnetic measurements as a function of temperature point out the precursor effects of the magnetic phase transitions involving a strong coupling between spins, lattice and electric order, even above the Néel temperature.