High-pressure effect on the crystal and magnetic structures of the frustrated antiferromagnet YMnO3

High-resolution structure studies and magnetoelectric coupling of relaxor multiferroicPb(Fe0.5Nb0.5)Sim1, Peets2, Lee3 et al. 2014Phys. Rev. B15060View full textAdd to dashboardCite

“…Fitting (shown by a solid line) results in a Debye temperature Θ D of only 150 K, whereas b = 1.5, V 0 = 64.582Å 3 , and Q = 3.87(6) × 10 −17 J are similar to parameters used for other materials [24][25][26]. We note that the resulting Debye temperature is abnormally small, leading to a bulk modulus around 600 GPa for a typical Grüneisen parameter of order one, which is high for an oxide: For example, we earlier found bulk moduli of 120 GPa for YMnO 3 [27] while 250 GPa has been reported for MgSiO 3 [28]. Note that this assumption about the Grüneisen parameter is crude, and so our estimate of the bulk modulus should be taken with caution.…”

High-pressure structural stability of multiferroic hexagonalRMnO3(R=Y, Ho, Lu)

“…Diffraction patterns of REMnO 3 are shown in Fig By neutron diffraction, the structure under pressure has been determined up to 6 GPa [16,17]. Here it is found that the oxygen position parameters do not significantly vary with pressure.…”

“…The Mn magnetic moment is suppressed. At 10 K, the ordered magnetic moment values are reducing with rates dM/dP = − 0.35 µB GPa −1 in YMnO 3 and -0.08 µB/Mn GPa −1 in LuMnO 3 [16,17]. The decrease in LuMnO 3 is due to an enhancement of the geometrical frustration effects on the triangular lattice.…”

“…A spin-liquid state due to magnetic frustration on the triangular lattice forms by Mn ions at normal pressure and T > T N = 70 K, and an ordered triangular AF state occurs with the symmetry of the irreducible representation Г1 arises at T < T N . The high-pressure effect leads to a spin reorientation of Mn magnetic moments and a change in the symmetry of the AF structure, which can be described by a combination of the irreducible representations Г1 and Г2 [16,17,18]. High pressure induces a spin-liquid phase in YMnO 3 , coexisting with the suppressed long-range AF order.…”

“…Under high pressure conditions, the dielectric and magnetic properties of Hex-REMnO 3 have been studied [14,15,16,17,18] up to 6 GPa. In those works, the hexagonal structure is not changed [15,19].…”