Transition Metals

The transition metals are the metallic elements that serve as a bridge, or transition, between the two sides of the periodic table. Compared to other metals, the transition metals have high melting points and densities, and they (and their compounds) can act as catalysts.

Many transition metals are technologically important, including titanium, iron, nickel, and copper. Ancient civilisations knew about iron, copper, silver, and gold. The oldest surviving iron artefacts were made from iron meteorites, and contain specific alloys of iron and nickel that occur only in extraterrestrial objects. It was thousands of years before humans developed the technology to extract pure iron from its naturally occurring ores, after which iron tools became common.

Scientists from the University of Oxford and the University of Wisconsin-Madison teamed up with Diamond to see whether they could induce tiny magnetic vortices to form in a form of iron called haematite (rust, essentially). Vortices are fascinating, dynamic structures that naturally occur in sizes ranging from the immense (think tornado) to the microscopic. In some cases, their formation is thwarted by long-range forces, and the long-range forces in ferromagnetic materials (like the magnets on your fridge) make it difficult for tiny magnetic vortices to form. But haematite is an antiferromagnet, in which long-range forces don’t occur. So the scientists went looking for magnetic vortices in haematite, and not only found them, but were able then to transfer them from the haematite into a ferromagnetic material. Ultimately, this could lead to a new generation of electronic devices that move beyond the silicon we currently rely on. Read more here.

The coastal regions downstream from glaciers are highly productive ecosystems, one example of which is the large summer phytoplankton bloom in the Labrador Sea. One possible explanation for this high productivity is that meltwater from glaciers is supplying iron to these areas. Iron is an essential micronutrient for marine phytoplankton, and in large areas of the world’s oceans its availability is a limiting factor for growth for these primary producers, on which the marine food web depends. Iron supply is also a critical factor in dictating the strength of the ocean ‘biological pump’, which affects concentrations of carbon dioxide in the atmosphere, and hence the global climate. Glaciers and ice sheets are a significant source of nanoparticulate iron, but how important it is to the marine environment is still a bit of a mystery. A team of researchers from the UK and Germany used high-resolution imaging and spectroscopy at Diamond to investigate the amount and type of iron present in glacial sediments, and found they could be very important indeed. Read more here.

Humans have been using iron to make weapons, tools and ceremonial items for more than 20,000 years, but once these objects have been excavated they are at risk from corrosion, which can be accelerated in the presence of chlorine. Each recovered artefact has to be conserved to prevent it from deteriorating in the presence of air and water. Until now, a comparison of the effectiveness of different conservation methods has been hampered by the variable nature of both the artefacts found, and the environment in which they were buried.

Learn more

Alzheimer’s disease is a neurodegenerative disease that is associated with dementia and shortened life expectancy. The disease is characterised by the formation of protein plaques and tangles in the brain that cause damage, and there’s a link to elevated iron levels in certain regions of the brain.

 Volcanic eruptions can be triggered (or ended) by changes in the magma (molten rock) in or beneath the planet’s crust. The cause of these changes is often thought to be a result of the mixing of different batches of magma in the ‘plumbing system’ below the volcanoes. Volcanologists are working on detecting and understanding these changes, by examining volcanic rock samples, with the aim of being able to accurately forecast future eruptions.

The spinach-guzzling superhero Popeye helped to increase American spinach consumption by a third, and the character's creator chose that vegetable because of its high iron content.

There is a very pervasive story that this was all based on a typo. According to the story, in 1870, German chemist Erich von Wolf correctly measured the amount of iron in spinach. However, when he wrote up his notes, he put the decimal point in the wrong place, recording that spinach contained 35 milligrams of iron per 100 grams, rather than 3.5 mg.

This botanical myth was thoroughly debunked by Dr Mike Sutton in 2010, and the University of Bristol's 'Picture It...' chemistry website has an up-to-date article about the real nutritional value of spinach.