%0 Journal Article %T Field-induced spin density wave and spiral phases in a layered antiferromagnet %+ Oak Ridge National Laboratory [Oak Ridge] (ORNL) %+ Magnétisme et Diffusion Neutronique (MDN) %+ Geballe Laboratory for Advanced Materials and Department of Applied Physics %A Stone, M. B. %A Lumsden, M. D. %A Garlea, V. O. %A Grenier, Beatrice %A Ressouche, Eric %A Samulon, E. C. %A Fisher, I. R. %< avec comité de lecture %@ 1098-0121 %J Physical Review B: Condensed Matter and Materials Physics (1998-2015) %I American Physical Society %V 92 %P 020415 %8 2015 %D 2015 %R 10.1103/PhysRevB.92.020415 %K Bose-Einstein Condensation %K Neutron Powder Diffraction %Z PACS number(s): 75.10.Jm, 75.30.Et, 75.40.Gb %Z Physics [physics]Journal articles %X We determine the low-field ordered magnetic phases of the S = 1 dimerized antiferromagnet Ba$_3$Mn$_2$O$_8$ using single-crystal neutron diffraction. We find that for magnetic fields between $\mu_0$$H$ = 8.80 T and 10.56 T applied along the [1$\bar 1$0] direction the system exhibits spin density wave order with incommensurate wave vectors of type ($\eta$,$\eta$,$\epsilon$). For $\mu_0$$H$ > 10.56 T, the magnetic order changes to a spiral phase with incommensurate wave vectors only along the [$hh$0] direction. For both field-induced ordered phases, the magnetic moments are lying in the plane perpendicular to the field direction. The nature of these two transitions is fundamentally different: the low-field transition is a second-order transition to a spin density wave ground state, while the one at higher field, toward the spiral phase, is of first order. %G English %L cea-01745410 %U https://cea.hal.science/cea-01745410 %~ CEA %~ INAC-SPSMS %~ DSM-INAC %~ CEA-DRF %~ IRIG %~ CEA-GRE