Researchers have probed samples of metal bismuth, and found a completely unexpected property - under certain conditions, the solid metal can retain a type of 'structural memory' of its liquid state.
The fact that scientists have found a new property of metals is exciting enough. But this also means solid bismuth can go from being repelled by a magnetic field (diamagnetic) to being attracted to a magnetic field (ferromagnetic), which could lead to a whole new way of creating materials with unique properties.
The phases of matter we learn about in high school, such as liquid, gas, and solid, are all defined by the way molecules in matter are arranged depending on external conditions. For example, liquid water freezes and contracts together into ice, or relaxes and boils into steam.
But bismuth is one element that's not so straightforward. It's most commonly found in solid form, but under increasing pressure and temperature conditions, it can undergo a broad array of phase transitions. For example, scientists have observed eight different types of solid phases in the metal so far.
So far, so weird.
But it gets stranger. One of the most interesting properties of bismuth is that it's usually repelled by a magnetic field when it's a solid, thanks to a phenomenon known as diamagnetism, but under certain high pressure and high temperature conditions - which usually coincide with it being in a liquid state - the metal can become ferromagnetic, or attracted to a magnetic field.
Because of this weird property, scientists have used bismuth to make a lot of important observations about the effect of magnetic fields on electrical conductivity (usually bismuth is an incredibly weak conductor).
And now they've found something else about the metal - it appears to be capable of retaining structural memory of its liquid phase, even when it's a solid.
More:
https://www.sciencealert.com/scientists-just-found-a-totally-unexpected-property-in-a-solid-metal-it-remembers-its-liquid-state
