Research aids understanding of heat-induced material changes

Research conducted by Southampton and Cambridge universities has led to a better understanding of the changes materials undergo when rapidly heated.

Using equipment and MEMS sensors from Mettler-Toledo, scientists from Southampton University’s Optoelectronic Research Centre and Cambridge University’s Department of Materials Science were able to probe the behaviour of phase-change memory materials — the semiconductors that store information in the next generation of electronics — as they were heated at rates up to 10,000°C per second.

According to a statement, insight and a detailed understanding of measurement results was provided by Prof Lindsay Greer, from Cambridge University’s Department of Materials Science, whose analysis showed that crystal growth rates differed considerably from other materials such as glass and silicon and the behaviour of these materials on such rapid heating was not as expected.

The results, which are published in Nature Materials, show that crystal growth rates are much faster than previously believed in these materials and that the growth behaviour is independent of the surroundings.

The research provides a method of directly screening materials for improved memory performance, which could lead to faster, smaller and less power-hungry smartphones, MP3 players and computers.

Prof Dan Hewak from Southampton University said: ‘We have been studying novel glasses and phase-change materials for two decades here at the Optoelectronics Research Centre.

‘However, our understanding of what happens when these materials are heated — that is, their crystallisation and melting behaviours — has been limited to heating rates of about 10°C per minute using conventional thermal analysis.

‘In reality, in the memory devices we fabricate, heating rates are millions of times faster and it is reasonable to expect that in order to improve these devices, an understanding of their properties at the same heating rates they will be used is needed.’