Welcome to Hafnium, home of chips, bombs and conspiracies

We are moving into one of the two times of year when the heartbeat of IT journalism develops arrhythmia. People are on holiday or moving around the place, thoughts are turning to enjoying or surviving the break (according to taste), and the wiser technologist knows that big announcements will fall on icy ground. Questions go unanswered or unasked.

That's OK – more time to research interesting stuff and apply the unction of legitimate inquiry to the scabies of unfulfilled curiosity. Even here, the jobbing journalist is scuppered: forget those endless arguments about the colour of Wikipedia's soul. When it comes to turning out a few hundred words on why something obscure is interesting, it's almost unbeatable. And who wants to spend a day hacking around after the good bits when the response of the readers is "Oh, you can look up Wikipedia too? Well done!".

Take hafnium. The latest desperately obscure element to get its fifteen minutes of material science fame, it's not something I knew as anything other than a bit player in a Tom Lehrer song. A moment after asking Wikipedia, I knew it was named after the Latin name for Copenhagen, it's usually found with zirconium (which as a metal has half hafnium's density but is otherwise so similar the two are nigh impossible to separate), and it's got an exceptionally high neutron capture cross-section. That means it gets used in nuclear reactors as a moderator, snatching just enough neutrons to keep things burbling along without getting too hot.

Wiki didn't say why it's been chosen for the latest batch of transistors, though. It can be used to make an insulator that's electrically very thin for its physical size – like particularly clear glass that can be made into thick windows without obscuring the view. Hafnium isn't the only material that can do this, but it is very good – it's got the right number of electrons distributed in the right orbitals around the atom to let it be easily influenced by electrical charge. Prevent the electrons from actually flowing by putting the hafnium in an insulating compound, and the atoms will get easily polarised, each passing the influence of the electron charge across to its fellows without the electrons actually flowing. Just as importantly, it forms the right sort of bonds with the other compounds in a transistor to make repeatable, reliable and finely configurable devices. Sign it up, sergeant-major.

But Wiki (is there a decent contraction for Wikipedia?) did say something else. A particular radioactive isomer of hafnium, Hafnium-178m2, is a prime candidate for X-ray induced gamma emisson, Hit it with enough of the right sort of energy, some think, and it'll undergo gamma decay – in other words, go bang like the atomic weapon it's just become.

Now, induced gamma emission isn't particularly controversial: it's been known for ages that if you slap the right sort of atom around with particles like protons or neutrons, it'll split up with more energy than a celebrity divorce. For people who like making things go bang, though, the idea is somewhat marred by the need to produce high energy particles on the battlefield. You can't lug an accelerator around in a weapon that has to go somewhere else before detonating – and as that's the point of most weapons, particle induced gamma decay has been a non-starter.

X-rays are different. While it's by no means easy to create enough of those in a handy-dandy portable form, it's at least plausible. The result could be a very powerful, very controllable, very small atomic weapon that doesn't have the drawbacks of the traditional sort: it doesn't have to have a critical mass of radioactive material, and it doesn't have to have any moving parts or complex shaped explosives. In terms of ruining your weekend, a gram of Hf-178m2 would be roughly the same as 500 pounds of TNT. If it works.

If it works. I soon found myself wandering through a familiar maze of claim and counter-claim, all clipped from the spiky hedge of military- tinged conspiracy theory. Cold fusion! Cover-ups! Unrepeatable experiments! Battling theories! They're all here.

I don't pretend to know what the truth is here – has research been deliberately stymied by a nervous establishment which doesn't fancy everyone getting their own hafnium bomb? Is the basic physics not right anyway? Is The Truth leaking out anyway? You're welcome to go out and do your own research here – I encourage it – as something to while away the long dark hours of turkey digestion to come.

Meanwhile, enjoy your hafnium-laced chips. Get 'em while they're hot.