Magnetic structure of hexagonalRMnO3(R=Y, 

Elastic anomalies associated with structural and magnetic phase transitions in single crystal hexagonal YMnO3

“…Mn(x) position [38] 0.324 72 [15] 0.317 7(9) [35] 0.333 0(17) [29] 0.320 8(18) [39] (at 10 K) 0.333 5 (6) largest amount of stiffening was observed for C 66 (∼3%) and C 11 (∼1%), in comparison with C 33 and C 44 (<0.1%), corresponding to a stronger influence of magnetic interactions directed within the (001) plane rather than perpendicular to it. Using a Landau description the relevant strain/order parameter coupling term was determined to be λe 2 S 2 ⊥ , where e is a strain, λ is a strain/order parameter coupling constant, and S ⊥ is the in-plane spin component representing the magnetic order parameter.…”

“…Antiferromagnetism arises from the Mn 3+ ions, with S = 2 spin state, which make up a single magnetic sublattice. The manganese ions sit in a pseudotwo-dimensional triangular arrangement parallel to the (001) plane, with 120 • angles between the moments on neighbouring Mn 3+ ions [29], and a significant degree of magnetic frustration is revealed by large Weiss-Néel point ratios of ∼10 [2]. The low temperature magnetic structure [25].…”

“…of YMnO 3 has never been completely confirmed although current consensus appears to be that it belongs to either P6 3 cm or P6 3 cm which form a homometric pair (magnetic structures that are indistinguishable via neutron diffraction), the latter structure being favoured by optical second harmonic spectroscopy [29][30][31][32][33][34].…”

“…The magnetoelastic coupling effect in YMnO 3 has been the subject of much work in recent years and a series of neutron diffraction experiments has been carried out to monitor changes in lattice parameters and atomic positions at T N [7,10,29,[35][36][37]. Monitoring of changes in atomic positions and bond lengths is difficult due to the small changes involved.…”

Phonons and hybrid modes in the high and low temperature far infrared dynamics of hexagonal TmMnO3

“…And, as in any other RMnO 3 (R=Rare Earth), interplane exchange interactions are expected to be about two orders of magnitude weaker [11] but still play a significant role in the origin of multiferroicity. [12,13] Thulium ions are in cages surrounded by seven oxygens (TmO 7 ) in a trivalent state and occupy two non-equivalent lattice sites.…”