Hot attraction in bimetals: A cyano-bridged vanadium-niobium bimetal assembly with a Curie temperature of 210 K

January 24, 2012

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 for applications.

Explore further: Towards the magnetic fridge

More information: Shin-ichi Ohkoshi, A Cyano-Bridged Vanadium–Niobium Bimetal Assembly Exhibiting a High Curie Temperature of 210 K, European Journal of Inorganic Chemistry, dx.doi.org/10.1002/ejic.201101219

Related Stories

Towards the magnetic fridge

April 21, 2006

Researchers at the University of Cambridge have discovered a material that gives a whole new complexion to the term 'fridge magnet'. When this alloy is placed in a magnetic field, it gets colder. Karl Sandeman and his co-workers ...

Three-dimensional polymer with unusual magnetism

November 13, 2006

Up to now it has not been possible to fabricate magnets from organic materials, like for example plastics. Recently, however, experiments at the Forschungszentrum Dresden-Rossendorf (Germany) in collaboration with an international ...

Novel magnets made from the strongest known hydrogen bond

December 6, 2006

A team of scientists from the US, the UK and Germany has been the first to make a magnetic material constructed from nature's strongest known hydrogen bond. Hydrogen bonds are responsible for many of the properties of water ...

Scientists make magnetic new graphene discovery

April 14, 2011

(PhysOrg.com) -- University of Maryland researchers have discovered a way to control magnetic properties of graphene that could lead to powerful new applications in magnetic storage and magnetic random access memory.

Recommended for you

Brazilian wasp venom kills cancer cells by opening them up

September 1, 2015

The social wasp Polybia paulista protects itself against predators by producing venom known to contain a powerful cancer-fighting ingredient. A Biophysical Journal study published September 1 reveals exactly how the venom's ...

Naturally-occurring protein enables slower-melting ice cream

August 31, 2015

(Phys.org)—Scientists have developed a slower-melting ice cream—consider the advantages the next time a hot summer day turns your child's cone with its dream-like mound of orange, vanilla and lemon swirls with chocolate ...

Antibody-making bacteria promise drug development

August 31, 2015

Monoclonal antibodies, proteins that bind to and destroy foreign invaders in our bodies, routinely are used as therapeutic agents to fight a wide range of maladies including breast cancer, leukemia, asthma, arthritis, psoriasis, ...

A marine creature's magic trick explained

September 2, 2015

Tiny ocean creatures known as sea sapphires perform a sort of magic trick as they swim: One second they appear in splendid iridescent shades of blue, purple or green, and the next they may turn invisible (at least the blue ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

Graeme
not rated yet Jan 24, 2012
210K is not what we would normally call a high temperature. I am surprised that this is useful for detecting humidity, as it would condense as frost on the cold detector. Lets hope they can get it up to room temperature.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.