title: Cu(II)-Dy(III) and Co(III)-Dy(III) based single molecule magnets with multiple slow magnetic relaxation processes in the Cu(II)-Dy(III) complex.
abstract: Two dinuclear Schiff-base complexes [Cu(II)Dy(III)] and [Co(III)Dy(III)] have been synthesized and structurally characterized. The AC susceptibility measurements taken at BDC = 0.2 T show a slow magnetic relaxation typical for single-molecule magnets. Unusual is the presence of three relaxation branches in [Cu(II)Dy(III)]; the slowest (low-frequency) process possesses the barrier to spin reversal of U/kB = 2.8 K and an extrapolated relaxation time as slow as τ0 = 0.11 s. The intermediate-frequency process is typical for SMM of this class with U/kB = 122 K and τ0 = 9.9 × 10(-7) s; an onset of the high-frequency process is evidenced and this is the fastest. In contrast, the [Co(III)Dy(III)] complex free of exchange coupling exhibits only a single relaxation path with SMM parameters U/kB = 113 K and τ0 = 7.0 × 10(-9) s.
authors.affiliation: Department of Chemistry, Jadavpur University, Kolkata, West Bengal, India. m_ali2062@yahoo.com.
authors.forename: Malay
authors.initials: M
authors.lastname: Dolai
authors.forename: Mahammad
authors.initials: M
authors.lastname: Ali
authors.forename: Ján
authors.initials: J
authors.lastname: Titiš
authors.forename: Roman
authors.initials: R
authors.lastname: Boča