(Zhang, et al., National Science Review)
Down on an atomic level, glass may be a jumbled mess of atoms, which makes it easily susceptible to distortion & cracking. Now, chemists have discovered the way to arrange the atoms within glass such how , the resulting material can even rival the strength of diamonds.
A team of materials scientists from Yanshan University in China has discovered the critical proportion of crystallized and amorphous carbon needed to make a glass with remarkable properties that will not weaken under intense pressure.
The mechanical properties of material often come right down to the way its building blocks link together. Diamond’s notorious toughness is decided by the 4 bonds every single one among its carbon atoms makes with its neighbors. Though these bonds bring a solid bridge, they also don’t leave any electrons spare to hold a current, effectively making diamond an insulator.
Glassy solids do not have repeating patterns, a minimum of on a general scale. Their overall structure is more or less what you get when a liquid’s particles all drop by place once the temperature drops low enough.
Depending on the constituent ingredients, however, glassy materials can have a surprising degree of structure up close. Their disordered arrangement also allows for a good range of optical & mechanical properties that creates them better fitted to certain technologies.
Glasses that are supported metals should combine the benefits of both, lending a degree of strength that crystalline metals do not have , while still being conductive.
Determining what a glassy state of carbon might behave like, however, is hard to predict supported theory alone.
So the Yanshan researchers experimented, squishing spheres of carbon atoms called ‘buckyballs’ under intense pressure of around 25 gigapascals (just under 250,000 atmospheres) then baking the mush at temperatures between 1,000 and 1,200 degrees Celsius (about 1,800 to 2,200 degrees Fahrenheit).
Subjecting the products, dubbed AM-I, II, & III, to a litany of tests, the chemists mapped the way the atoms bonded with each other , showing all of them operated as a semiconductor on A level comparable amorphous silicon.
But it had been the mechanical properties of the third result that really stood out.
Diamond is characteristically referred to as one among the toughest known substances. a standard measure of hardness, called the Vickers hardness test, actually uses a diamond tip to indent material. The harder material , the greater the force (measured in gigapascals) required to go away a large mark.
Scratching another diamond might require somewhere between 60 and 100 gigapascals, counting on whether it’s natural or made with care during a lab.
The glassy material AM-III measured somewhere between 110 and 116 gigapascals on the Vickers hardness test, making it the toughest amorphous solid so far . Running a slither of the substance along the flat face of a natural diamond left a transparent score line.
Producing enough of material to use widely in commercial processes would be an expense few would hand over on immediately . In time, enough could be made to function a replacement for silicon transistors utilized in high-pressure environments.
Given how experimental this glass development was, it’s possible there’s more to be found by squashing & cooking other carbon allotropes, like graphene, at a variety of pressures and temperatures.
Materials science is well into the carbon age lately , arising with ingenious new ways to place mechanical and electrical properties of variously-arranged carbon atoms to figure .
How we’ll use AM-III is tough to mention immediately, but at some point it just might become an electrical engineer’s ally .
This research was published in National Science Review.
