30-Nov-2021 - Bundesanstalt für Materialforschung und -prüfung (BAM)

New insights into crystallisation processes

The better the results of the crystallisation process of materials can be controlled and predicted, the greater the chances of producing crystals that have specific characteristics and allow material properties to be optimised. Scientists at the Bundesanstalt für Materialforschung und -prüfung (BAM) in Berlin have presented new findings on crystal structure, which have been published in the journal PNAS of the National Academy of Sciences of the United States.

Crystals are commonly regarded as the epitome of perfect order - a notion that has even led to them being attributed magical powers. Their orderly structure suggests that their growth also occurs in a very regular and orderly manner. In recent years, however, studies have challenged this "classical" view, and it is now considered likely that the growth of some crystalline materials can also occur in other ways.

To shed light on this question, a team of BAM researchers intensively analysed anhydrite crystals from Mexico and their growth history. They used crystals from the famous Naica mine in northern Mexico for their investigations. Natural caverns of the ore mine contain crystals that have grown over many millennia and are therefore particularly informative for crystallographers.

In their investigations, the scientists took a closer look at defects in the crystal samples in the nanometre to millimetre range and mapped the internal structure of the mineral in detail. These analyses showed that misalignment at the nanoscale spreads over length scales, eventually leading to the formation of voids inside the crystal that can even measure several tens of microns or more. They also found that these misalignment defects come from a so-called "seed of imperfection", leading to a macroscopic single crystal whose fragments do not fit together inside - even if the mineral appears perfect on the outside. The team thus came to the insight that misalignments on the nanoscale are amplified a million-fold during the growth process.

This new insight adds decisively to the concept of non-classical nucleation and crystalline growth processes. It is of great relevance for the development and production of new and improved materials.

Facts, background information, dossiers
  • crystal structures
More about BAM
  • News

    Glowing nanocrystals

    Tiny luminous particles are being used in more and more products today: from smartphones to OLED televisions to car headlights. Precise knowledge of the luminosity is crucial for industry. The Federal Institute for Materials Research and Testing (BAM) is developing reliable measurement meth ... more

    Aviation safety: Rapid test for harmful microbes in kerosene developed

    Fuels such as kerosene or diesel can be contaminated by fungi or bacteria. The microorganisms settle in the liquid itself, on the inner walls of tanks and pipes or in fuel filters and feed on carbon atoms. Since the fungi and bacteria multiply well in this environment, they can form a strea ... more

    Analytik Jena and BAM agree to cooperate in research

    The Bundesanstalt für Materialforschung und -prüfung (Federal Institute for Materials Research and Testing, BAM) and Analytik Jena AG have agreed to cooperate extensively in the research and development of optical spectrometry in the area of elemental analysis. The two parties signed a corr ... more