By using diamond-tipped tools to apply pressure to the GST, the researchers found they could change the properties of the alloy from an amorphous to a crystalline state and thus reduce the electrical resistivity by about four orders of magnitude. By slowing down the change from an amorphous state to a crystalline state, the scientists were also able to produce many varying states allowing more data to be stored on the alloy.

GST is called a phase-change material because, when exposed to heat, an area of the alloy can change from an amorphous state, in which the atoms lack an ordered arrangement, to a crystalline state, in which the atoms are neatly lined up in a long-range order.

An illustration of how the diamond-tipped tools were used to compress GST

The two states are then used to represent the computer digital language of ones and zeros.

In its amorphous state, GST is more resistant to electric current. In its crystalline state, it is less resistant