title: Partial order in the non-Fermi-liquid phase of MnSi.
abstract: Only a few metallic phases have been identified in pure crystalline materials. These include normal, ferromagnetic and antiferromagnetic metals, systems with spin and charge density wave order, and superconductors. Fermi-liquid theory provides a basis for the description of all of these phases. It has been suggested that non-Fermi-liquid phases of metals may exist in some heavy-fermion compounds and oxide materials, but the discovery of a characteristic microscopic signature of such phases presents a major challenge. The transition-metal compound MnSi above a certain pressure (p(c) = 14.6 kbar) provides what may be the cleanest example of an extended non-Fermi-liquid phase in a three-dimensional metal. The bulk properties of MnSi suggest that long-range magnetic order is suppressed at p(c) (refs 7-12). Here we report neutron diffraction measurements of MnSi, revealing that sizeable quasi-static magnetic moments survive far into the non-Fermi-liquid phase. These moments are organized in an unusual pattern with partial long-range order. Our observation supports the existence of novel metallic phases with partial ordering of the conduction electrons (reminiscent of liquid crystals), as proposed for the high-temperature superconductors and heavy-fermion compounds.
authors.affiliation: Physikalisches Institut, Universität Karlsruhe, D-76128 Karlsruhe, Germany. Christian.Pfleiderer@physik.uni-karlsruhe.de
authors.forename: C
authors.initials: C
authors.lastname: Pfleiderer
authors.forename: D
authors.initials: D
authors.lastname: Reznik
authors.forename: L
authors.initials: L
authors.lastname: Pintschovius
authors.forename: H V
authors.initials: HV
authors.lastname: Löhneysen
authors.forename: M
authors.initials: M
authors.lastname: Garst
authors.forename: A
authors.initials: A
authors.lastname: Rosch