title: Long-range magnetic ordering in magnetic ionic liquid: Emim[FeCl4].
abstract: Up to now most of the magnetic ionic liquids containing tetrachloroferrate ion FeCl(4) have evidenced a paramagnetic temperature dependence of the magnetic susceptibility, with only small deviations from the Curie law at low temperatures. However, we report on the physical properties of 1-ethyl-3-methylimidazolium tetrachloroferrate Emim[FeCl(4)], that clearly shows a long-range antiferromagnetic ordering below the Néel temperature T(N)≈3.8 K. In addition, the field dependence of the magnetization measured at 2 K is characterized by a linear behaviour up to around 40 kOe, while above this field the magnetization becomes saturated with a value of 4.3 μ(B)/Fe, which is near the expected fully saturated value of 5 μ(B)/Fe for an Fe(3+) ion.
authors.affiliation: CITIMAC, Facultad de Ciencias, Universidad de Cantabria, Santander, Spain.
authors.forename: I
authors.initials: I
authors.lastname: de Pedro
authors.forename: D P
authors.initials: DP
authors.lastname: Rojas
authors.forename: J
authors.initials: J
authors.lastname: Albo
authors.forename: P
authors.initials: P
authors.lastname: Luis
authors.forename: A
authors.initials: A
authors.lastname: Irabien
authors.forename: Jesús A
authors.initials: JA
authors.lastname: Blanco
authors.forename: J Rodríguez
authors.initials: JR
authors.lastname: Fernández