Nobel Laureate in Chemistry describes the quest to have quasicrystals recognized

The 1982 discovery of these crystals sparked skepticism from the scientific community until they were finally accepted after more than a decade, says Israeli Daniel Shechtman.

By Elton Alisson

Agência FAPESP – One of the most important discoveries in chemistry in decades – with applications in several areas, including materials engineering – faceds skepticism from the majority of the scientific community before being accepted more than a decade later. The final acceptance of the discovery culminated in a Nobel Prize.

The questsaga for the recognition and conafffirmation of quasicrystals – an ordered structures that are similar to like crystals butthat are not periodic – was recently the topic of a recent lecture given by Daniel Shechtman, researcher at Technion – Israel Institute of Technology and 2011 Nobel Laureate in Chemistry for the discovery, at the 64th Annual Meeting of the Brazilian Society for the Progress of Science (SBPC) in São Luís, Maranhão.

In April 1982, aswhile he examined an aluminum and manganese alloy under an electron transmission microscope, Shechtman found an image that contradicted the laws of nature.

Until then, it was believed that atoms in all solid matter were arranged in symmetric patterns that are repeated periodically and consisteantly and that this repetition was fundamental for creating a crystal (a, like diamond, for examples).

The image that Shechtman observed, however, showed that the atoms in a crystal could be grouped in a pattern that simply would never repeat itself.

In discussing the discovery with colleagues in the laboratory, the reactions varied from encouragement to publish his results to total rejection of the idea. “The head of the laboratory where I worked put a book on diffraction on my table and told me I should take it because what I said was against everything that had ever been published. According to him, what I was proposing simply did not exist. Sometime later, I was invited by my boss to leave the group, which I ended up doing,” he recalls.

In 1983, Shechtman submitted the first article describing the discovery to a chemical journal. The article periodical in the chemistry area and it was rejected based on by peer- reviews. The reviewersy  suggested that the results of the study be published in a metallurgical journaly magazine, an option that Shechtman and his collaborators pursued.

In 1984, a summary of the original article on quasicrystals was submitted and accepted by the prestigious Physical Review Letters, and this publicationwhich contributed to a broadergreater acceptance of the discovery.

Nevertheless, even following this publication, the rejection of quasicrystals persisted in certain circles. “After publication of the article, I began to receive several calls from scientists in different areas, communicating that they were discovering other quasicrystals, but part of the scientific community still was not convinced of the importance of the discovery,” he recalled.

According to Shechtman, one of the scientists whothat most doubted and belittled quasicrystals was none otherless than Linus Pauling (1901-1994), the only person to singlehandedly ever win a Nobel in two different areas - Chemistry and Peace.

Winner of the Nobel Prize in Chemistry in 1954, for studies on the nature of chemical bonds, Pauling said that quasicrystals or quasimaterials did not exist, but rather “quasiscientists”, in a mocking pun referring toabout the discovery. “Pauling was a brilliant scientist, but lacked humility and thought he knew everything,” said Shechtman.

Despite the divergences in their relationship stemming from their views onbetween quasicrystals, Shechtman recalls that he had several points of agreement with Pauling, with whom he met sporadically and maintained contact for a long time.

Once, Pauling sent him a letter proposing that that the two publish a scientific article together, to which Shechtman responded affirmatively under the condition thatas long as Pauling accepted the existence of quasicrystals.

Pauling replied that he would have to wait a little longer for the existence of quasicrystals to be proven and to consolidateement the idea of a scientific article together. “When he died, the quaisperiodicity of crystals had already become nearly totally accepted,” said Shechtman. 

Proof

According to Schechtman, a studyied conducted in 1987 in collaborationtogether with researchers from France and Japan, in which he analyzed the structure of a larger crystal than those initially studied, servedcontributed  to provide definitive proof of the existence of quasicrystals, ustilized today in the development of materials that ranginge from more resistant stainless steel to electronic and thermal insulation.

The results of the 1987 study were presented at an international crystallography congress in the same year in Australia. As a result, a scientific committee was created to evaluate quasicrystals. Finally, in 1992, the International Union of Crystallography changed the definition of crystal to include quasicrystals.

“For a long time, the order was synonymous with periodicity. Today, we know that the order could be periodical or almost periodical,” said Shechtman.

The Israeli scientist explaineds that quasicrystals were only discovered in 1982 because the transmission electron microscope, which permits theallows for study of material structure in greater details, had not been developed until then.

“Many researchers only use this type of microscope as a type of magnifying glass to obtain marvelous images, but one must be an expert in using this technique to explore all of its potential,” said Schechtman in his lecture to an audience of students and researchers that packed the Universidade Federal do Maranhão’s auditorium.

Investment in Science

In his first visit to Brazil, as part of a mission organized by Israel’s Ministry of Foreign Affairs, Shechtman said thatys he was impressed with the quality of the science that has been conducted in Brazil.

“A country with such immense biodiversity should make large investments in biological sciences, largely in the Amazon, to conduct integrated research with researchers in the area of chemistry, for example,” he opined. 

Shechtman is the second Israeli to win the Nobel Prize in Chemistry in an interval of just two years and the fourth in a decade. In 2009, Ada Yonath also receivedtook the prize along with side Venkatraman Ramakrishnan and Thomas Steitz for research about the structure of ribosomes, also in the area of crystallography.

“This is due to the investment Israel has made in all areas of sciences,” Shechtman commented to Agência FAPESP, in response to a question aboutregarding why Israel’sthe country emerging status asis becoming  a mill for Nobel prizes. 

Shechtman also stated that he conducted a science education project in Haifa, focused on children in kindergarten. In the project, participants conduct scientific experiments along with professors and parents with a view to stimulating interest and engagement in scientific activity.