Hot Attraction in Bimetals
Cyano-bridged bimetal assemblies attract attention because of their magnetic properties such as photomagnetization, humidity-induced magnetization, and nonlinear magneto-optical effect, which make them suitable for many applications.
A high Curie temperature is an asset for the use of such magnetic compounds in functional materials. Hexa-, hepta-, and octacyanometalates have been shown to have high Curie temperatures as a result of the high coordination number of their metal centers and the large superexchange interactions due to their diffuse 4d or 5d orbitals. Shin-ichi Ohkoshi and his co-workers at the University of Tokyo report the compound with the highest Curie temperature among octacyano-bridged bimetal assemblies in the Short Communication published in the European Journal of Inorganic Chemistry.
On the basis of initial studies indicating that an increased stoichiometry of vanadium(II) led to a higher Curie temperature in vanadium hexacyanochromate systems, Ohkoshi et al. used a small amount of VIII as catalyst to convert a higher proportion of VII in a similar system.
The magnetic properties of the resulting octacyano-bridged vanadium–niobium bimetal assembly were investigated. The compound, whose formula was determined to be K0.59VII1.59VIII0.41[NbIV(CN)8] •(SO4)0.50•6.9H2O, is ferrimagnetic, and the spins on VII and VIII are antiparallel with respect to the spin on NbIV. Its Curie temperature is 210 K. This high value is a result of the enhanced superexchange interaction through the VII–NC–NbIV pathway.
This study reports a strategy to synthesize magnetic materials with high Curie temperature to enhance the suitability of their magnetic properties for applications.
About the Author
Professor Shin-ichi Ohkoshi works in the Department of Chemistry, the University of Tokyo, and the Japan Science and Technology Agency. The Ohkoshi laboratory is specialized in the design and synthesis of magnetic materials with new and enhanced functionalities.
Author: Shin-ichi Ohkoshi, University of Tokyo (Japan), http://www.chem.s.u-tokyo.ac.jp/users/ssphys/english/index.html
Title: A Cyano-Bridged Vanadium–Niobium Bimetal Assembly Exhibiting a High Curie Temperature of 210 K
European Journal of Inorganic Chemistry, Permalink to the article: http://dx.doi.org/10.1002/ejic.201101219
All news from this category: Life Sciences
Articles and reports from the Life Sciences area deal with applied and basic research into modern biology, chemistry and human medicine.
Valuable information can be found on a range of life sciences fields including bacteriology, biochemistry, bionics, bioinformatics, biophysics, biotechnology, genetics, geobotany, human biology, marine biology, microbiology, molecular biology, cellular biology, zoology, bioinorganic chemistry, microchemistry and environmental chemistry.
Sustainable insulating material for shipping temperature-sensitive products
Researchers at the Institute of Natural Products Engineering at TU Dresden have developed an insulating material made from recycled paper for shipping temperature-sensitive foods and medicines. As part of a…
Helium nuclei at the surface of heavy nuclei discovered
Research team confirms a new nuclear property predicted by theory Scientists are able to selectively knockout nucleons and preformed nuclear clusters from atomic nuclei using high-energy proton beams. In an…