학술논문

Low-temperature heat capacity of the Mn(III)-porphyrin-TCNE ferrimagnetic complexes, [MnTXPP][TCNE][middle dot]2PhMe, (X=Cl, Br)
Document Type
Report
Source
Solid State Communications. July, 2005, Vol. 135 Issue 1-2, p71, 6 p.
Subject
Toluene -- Analysis
Manganese -- Analysis
Thermodynamics -- Analysis
Language
English
ISSN
0038-1098
Abstract
To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ssc.2005.03.064 Byline: Yasuhiro Nakazawa (a), Wendy Hoffman (b), Joel S. Miller (b), Michio Sorai (a) Abstract: Heat capacity measurements by thermal relaxation method were performed under the magnetic field (up to 8T) between 1.8 and 100K for the quasi-one-dimensional ferrimagnetic complexes, meso-tetrakis(4-chorophenyl or 4-bromophenyl)porphyrinato-manganese(III) tetracyanoethenide, [MnTXPP].sup.+[TCNE].sup.-*2PhMe (X=Cl, Br; PhMe=toluene). These complexes are ferrimagnets consisting of S=2 spins of manganese (III) cations and S=1/2 spins of [TCNE].sup.- organic radical anions that is arranged alternatively. At the critical temperatures ([approximately equal to]8K), below which a long-range magnetic order takes place, ac magnetic susceptibilities have been reported to exhibit sharp peaks. In contrast, no distinct heat capacity anomaly was observed, which is probably attributable to the low-dimensional effects. However, a magnet-caloric behavior characteristic of the alternating ferrimagnetic chain was observed. The contrastively enhanced behavior of the magnetic susceptibility is explained by the previously reported model assuming formation of magnetic domains in the crystal. Author Affiliation: (a) Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan (b) Department. of Chemistry, University of Utah, Salt Lake City, UT 84112-0850, USA Article Note: (footnote) [star]Contribution No. 93 from the Research Center for Molecular Thermodynamics.