title: Observation of a liquid-gas-type transition in the pyrochlore spin ice compound Dy2Ti2O7 in a magnetic field.
abstract: Low temperature magnetization measurements on the pyrochlore spin ice compound Dy2Ti2O7 reveal that the ice-rule breaking spin flip, appearing at H approximately 0.9 T applied parallel to the [111] direction, turns into a novel first-order transition for T<0.36 K which is most probably of a liquid-gas type. T-linear variation of the critical field observed down to 0.03 K suggests the unusual situation that the entropy release across the transition remains finite [approximately 0.5 (J/K) x mol-Dy] as T-->0, in accordance with a breaking of the macroscopic degeneracy in the intermediate "kagomé ice" state.
authors.affiliation: Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Sakakibara
authors.forename: T
authors.initials: T
authors.lastname: Tayama
authors.forename: Z
authors.initials: Z
authors.lastname: Hiroi
authors.forename: K
authors.initials: K
authors.lastname: Matsuhira
authors.forename: S
authors.initials: S
authors.lastname: Takagi