Your browser doesn't support javascript.
loading
Magnetic Fluctuations, Precursor Phenomena, and Phase Transition in MnSi under a Magnetic Field.
Pappas, C; Bannenberg, L J; Lelièvre-Berna, E; Qian, F; Dewhurst, C D; Dalgliesh, R M; Schlagel, D L; Lograsso, T A; Falus, P.
Afiliação
  • Pappas C; Delft University of Technology, Mekelweg 15, 2629 JB Delft, Netherlands.
  • Bannenberg LJ; Delft University of Technology, Mekelweg 15, 2629 JB Delft, Netherlands.
  • Lelièvre-Berna E; Institut Laue-Langevin, 71 Avenue des Martyrs, 38000 Grenoble, France.
  • Qian F; Delft University of Technology, Mekelweg 15, 2629 JB Delft, Netherlands.
  • Dewhurst CD; Institut Laue-Langevin, 71 Avenue des Martyrs, 38000 Grenoble, France.
  • Dalgliesh RM; STFC, ISIS, Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom.
  • Schlagel DL; Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA.
  • Lograsso TA; Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA.
  • Falus P; Institut Laue-Langevin, 71 Avenue des Martyrs, 38000 Grenoble, France.
Phys Rev Lett ; 119(4): 047203, 2017 Jul 28.
Article em En | MEDLINE | ID: mdl-29341765
ABSTRACT
The reference chiral helimagnet MnSi is the first system where Skyrmion lattice correlations have been reported. At a zero magnetic field the transition at T_{C} to the helimagnetic state is of first order. Above T_{C}, in a region dominated by precursor phenomena, neutron scattering shows the buildup of strong chiral fluctuating correlations over the surface of a sphere with radius 2π/ℓ, where ℓ is the pitch of the helix. It has been suggested that these fluctuating correlations drive the helical transition to first order following a scenario proposed by Brazovskii for liquid crystals. We present a comprehensive neutron scattering study under magnetic fields, which provides evidence that this is not the case. The sharp first order transition persists for magnetic fields up to 0.4 T whereas the fluctuating correlations weaken and start to concentrate along the field direction already above 0.2 T. Our results thus disconnect the first order nature of the transition from the precursor fluctuating correlations. They also show no indication for a tricritical point, where the first order transition crosses over to second order with increasing magnetic field. In this light, the nature of the first order helical transition and the precursor phenomena above T_{C}, both of general relevance to chiral magnetism, remain an open question.

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Idioma: En Revista: Phys Rev Lett Ano de publicação: 2017 Tipo de documento: Article País de afiliação: Holanda

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Idioma: En Revista: Phys Rev Lett Ano de publicação: 2017 Tipo de documento: Article País de afiliação: Holanda