The crystal grower
Kathleen Schindler works on producing technological crystals
What drives her, as she puts it, is the pleasure of working with her hands. The appeal of making something. The fascination of the material itself. The same was true during her time at Berlin’s Natural History Museum, where she worked with sample substances extracted from fossils. And it remains true today in Adlershof, where she oversees the slow growth of crystals under carefully controlled conditions.
Nearly three years ago, Kathleen Schindler took up her position as a technical staff member at the Leibniz-Institute for Crystal Growth (IKZ). She has yet to be bored. The contrary is true: “I’m constantly learning new things.” She is currently working in semiconductor manufacturing. This involves the production of high-quality single-crystal silicon from molten silicon—later processed, in several stages, by external partners into components for sensors, microchips and other electronic applications.
Her path into crystal growth was somewhat indirect. With a physicist father and a strong interest in science at school, a career in STEM seemed almost inevitable. Initially, Schindler studied geosciences and focused on natural materials. She then worked as a laboratory technician at the Museum of Natural History in Berlin, where she was involved in analysing stable isotopes from prehistoric bone material. These isotopes can reveal insights into the living conditions of early organisms, their diets, and even the climatic conditions they were exposed to. She first encountered IKZ during the Long Night of the Sciences—and discovered a field that has fascinated her ever since.
Her day-to-day work revolves around helping crystals grow—and that is more complex than it sounds. Everything has to be precisely aligned: temperature, speed, and the sequence of steps. Even minor deviations can cause the crystal to develop incorrectly.
One of the methods she works with is the so-called float-zone process. A silicon rod is heated at a specific point until it melts. This molten zone then moves slowly along the rod, leaving a newly formed crystal behind it. The process is gradual and steady—often taking several hours.
During this time, Schindler has to monitor everything closely. She checks the settings, observes how the process unfolds, and intervenes if necessary. It requires patience, concentration and a good intuitive sense of how things are progressing.
What makes the job distinctive is the combination of technology and hands-on work. Machines play a central role, but the work remains closely connected to the material itself. Much is learned through experience—for instance, recognising when a process is “going well” and when it is not.
The IKZ is regarded as a European centre of excellence in the research and production of technological crystals. Its products have a wide range of applications: They conduct heat or electricity, focus laser light, and reflect ultrasound. The institute’s expertise is equally broad and increasingly attractive to early-career researchers. In recent years, IKZ has steadily expanded the number of doctoral positions it offers. Around thirty PhD projects in crystal research and development are currently underway.
Dr. Winfried Dolderer for Adlershof Journal