Magnetic anisotropy of Co-II-W-V ferromagnet: single crystal and ab initio study

Chorazy, Szymon; Podgajny, Robert; Majcher, Anna M; Nitek, Wojciech; Rams, Michal; Suturina, Elizaveta A; Ungur, Liviu; Chibotaru, Liviu F; Sieklucka, Barbara

Publication

Magnetic anisotropy of Co-II-W-V ferromagnet: single crystal and ab initio study

Chorazy, Szymon
;
Podgajny, Robert
;
Majcher, Anna M
;
Nitek, Wojciech
;
Rams, Michal
;
Suturina, Elizaveta A
; Ungur, Liviu;
Chibotaru, Liviu F
;
Sieklucka, Barbara

Abstract

The novel layered {CoII3(2,2′-bpdo) 4(H2O)4[WV(CN)8] 2}·8H2O (1) network (2,2′-bpdo = 2,2′-bipyridine-1,1′-dioxide) is built of 2-D corrugated cyanide-bridged brick-wall skeletons parallel to the bc crystallographic plane. The coordination of chelating 2,2′-bpdo to Co(ii) gives 7-membered coordination rings. Magnetic and heat capacity measurements performed on monocrystalline samples reveal ferromagnetic ordering below TC of 6 K. Magnetic anisotropy of the ordered phase is represented by the easy axis oriented in the ac crystallographic plane. Bulk magnetic anisotropy is confronted with a local anisotropy of Co complexes: a strong axial anisotropy of trans,cis,cis-[CoII(μ-NC)2(H2O) 2(2,2′-bpdo)] moieties represented by gx(2) = 2.06, gy(2) = 2.95 and gz(2) = 7.30, and a planar anisotropy of trans,cis,cis-[Co II(μ-NC)2(2,2′-bpdo)2] represented by gx(3) = 5.40, gy(3) = 4.82 and gz(3) = 2.28, determined by CASSCF/RASSI/SINGLE-ANISO ab initio calculations. The experimental data are explained by the molecular field simulation of the magnetic structure using the above theoretical data. © The Royal Society of Chemistry 2013.

Keywords

Science & Technology, Physical Sciences, Chemistry, Multidisciplinary, Crystallography, Chemistry, PRUSSIAN BLUE ANALOG, COBALT(II) COMPLEXES, ELECTRON-TRANSFER, SPIN TRANSITION, BASIS-SETS, LIGAND, SPECTROSCOPY, FRAMEWORK, COMPOUND, POLYMERS