Methods / Equipment
The Crystal Growth group applies, modifies and develops techniques, such as traveling solvent floating zone TSFZ with infrared image furnace, Bridgman, solution/top seeded solution growth TSSG and Czochralski CZ methods to grow single crystals from the melt or solution. These range from isotopically pure semiconductors to fullerenes and transition metal oxides. Three floating zone furnaces, including Xenon-lamps heating up to 3000°C, are fully operational. They are used predominantly to grow large single crystals of transition metal oxides for neutron and optical spectroscopy. Vapor transport methods are modified to grow crystals of II-VI and III-V compounds with defined isotopic components from low amounts of source materials. Accurate characterization is done with the aim of obtaining high-quality single crystals, for instance, superconductivity and magnetism performed using SQUID, crystal compositions determined by SEM/EDX, structure and phase identified by X-ray diffraction method, polling of twin domains, differential thermal and thermal gravimetric analysis DTA/TG. Thermal behavior of investigated compounds can be direct in-situ observation under high temperature optical microscope HTOM.