A STUDY OF THE PHYSICAL PROPERTIES OF HIGH-TEMPERATURE SINGLE CRYSTALS.
Abstract:
A great variety of single crystals were grown and their physical properties studied. Crystals of metal oxides MnO, CoO, NiO, and mixed crystals of MnO-CoO, MnO-NiO, and CoO-NiO were grown by flame fusion and their electrical properties dielectric constant and conductivity and optical properties refraction and absorption as a function of frequency and temperature determined. The paraelectric properties of KTaO3 and the ferroelectric properties of KTaO3-NaTaO3 and KTaO3-KNbO3 were investigated as a function of composition and temperature. The dielectric properties of alkali halides, thallium halides, copper halides, and alkaline earth fluorides were measured over a wide frequency and temperature range. In semiconducting crystals Si, Ge, and GaAs, dielectric anomalies were detected at low temperatures. The method for crystal growth of fluorides was improved, and single crystals of KMgF3, RbMnF3, and YLiF4 were grown and their optical properties determined. The perfection of crystals was studied by ultraviolet and infrared absorption, by high precision lattice constant, and high precision density measurements. The mechanical properties were studied by microhardness measurement. The microhardness of mixed crystals was studied in particular. Author