Speaker
Dr
Zbigniew Tomkowicz
(Jagiellonian University, Institute of Physics)
Description
`[Co(NCS)$_2$py$_2$]$_n$ (py – pyridine) is composed of irregular ferromagnetic chains of Co(II) ions linked by the double NCS bridges. The coordination polyhedron of the Co(II) ion is a distorted octahedron built from equatorial two N and two S and two apical N atoms of the pyridine ligands. There are two inequivalent Co(II) ions which are magnetically coupled along chains in the $J_1 J_1 J_2$ sequence and the pyridine rings show an orientation disorder. Specific heat and magnetic study showed that [Co(NCS)$_2$py$_2$]$_n$ undergoes a phase transition to the ferromagnetic state at the Curie point of 3.7 K. Magnetic interactions have been determined on the base of the Ising model. By means of AC magnetic susceptibility measurements the magnetic relaxations were investigated. Using High Field-High Frequency ESR (HF-ESR) method the magnetic excitations were observed and explained in the frame of the Ising model in full accordance with magnetic studies. Energy barriers for magnetization reversal obtained from magnetic and HF-ESR measurements are compared and discussed.`
`Acknowledgments`
`This project was supported by the Deutsche Forschungsgemeinschaft (Project No. Na 720/5-1) and the State of Schleswig-Holstein. We thank Prof. Dr. Wolfgang Bensch for the access to his experimental facilities. ZT thanks the National Science Centre Poland for financial support granted under decision DEC-2013/11/B/ST3/03799. We thank the URZ of the FSU Jena for providing additional computational resources.`
Primary author
Dr
Zbigniew Tomkowicz
(Jagiellonian University, Institute of Physics)
Co-authors
Prof.
Christian Näther
(Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Straße 2, 24118 Kiel, Germany)
Dr
Michael Böhme
(Institut für Anorganische und Analytische Chemie, Friedrich-Schiller Universität Jena, Humboldtstr. 8, 07743 Jena, Germany)
Dr
Michal Rams
(Jagiellonian University, Institute of Physics)
Prof.
Vladislav Kataev
(Institute for Solid State Physics, IFW Dresden, Helmholtzstrasse 20, D-01069 Dresden, Germany)
Prof.
Winfried Plass
(Institut für Anorganische und Analytische Chemie, Friedrich-Schiller Universität Jena, Humboldtstr. 8, 07743 Jena, Germany)
Dr
Yulia Krupskaya
(Institute for Solid State Physics, IFW Dresden, Helmholtzstrasse 20, D-01069 Dresden, Germany)
