非表示:
キーワード:
-
要旨:
Strong spin-lattice coupling and prominent frustration effects observed in the 50 Fe-doped frustrated hexagonal IMG [http://ej.iop.org/images/0295-5075/110/3/37007/epl17080ieqn1.gif] (h)̑ext{LuMnO}_3} are reported. A Néel transition at IMG [http://ej.iop.org/images/0295-5075/110/3/37007/epl17080ieqn2.gif] {T_{\mathrm{N}}≈112\ ̑ext{K}} and a possible spin re-orientation transition at IMG [http://ej.iop.org/images/0295-5075/110/3/37007/epl17080ieqn3.gif] {T_{\mathrm{SR}}≈55\ ̑ext{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 6 3 cm space group. While the magnetic structure of LuMnO 3 belongs to the IMG [http://ej.iop.org/images/0295-5075/110/3/37007/epl17080ieqn4.gif] {Γ_4\ (P6'_3c'm)} representation, that of LuFe 0.5 Mn 0.5 O 3 belongs to IMG [http://ej.iop.org/images/0295-5075/110/3/37007/epl17080ieqn5.gif] {Γ_1\ (P6_3cm)} 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 IMG [http://ej.iop.org/images/0295-5075/110/3/37007/epl17080ieqn6.gif] {T_{\mathrm{N}}} and IMG [http://ej.iop.org/images/0295-5075/110/3/37007/epl17080ieqn7.gif] {T_{\mathrm{SR}}} which confirms strong spin-lattice coupling. Our results complement the discovery of room temperature multiferroicity in thin films of IMG [http://ej.iop.org/images/0295-5075/110/3/37007/epl17080ieqn8.gif] {h̑ext{LuFeO}_3 and would give impetus to study LuFe 1− x Mn x O 3 systems as potential multiferroics where electric polarization is linked to giant atomic displacements.
