title: Observation of a secondary slow relaxation process for the field-induced single-molecule magnet U(H2BPz2)3.
abstract: The trigonal prismatic complex U(H(2)BPz(2))(3) is characterized by single crystal X-ray diffraction and ac magnetic susceptibility measurements. The ac susceptibility data demonstrate the presence of multiple processes responsible for slow magnetic relaxation. Out-of-phase signals observed at ac switching frequencies between 1 and 1500 Hz in dc fields of 500-5000 Oe indicate a thermal relaxation barrier of ca. 8 cm(-1) for the molecule, with a temperature-independent process taking over at the lowest temperatures probed. Significantly, an unprecedented, slower relaxation process becomes apparent for ac switching frequencies between 0.06 and 1 Hz, for which a monotonic increase of the relaxation time with an applied dc field suggests a direct relaxation pathway.
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720-1460, USA.
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Rinehart
authors.forename: Katie R
authors.initials: KR
authors.lastname: Meihaus
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Long