| Abstract: | Conditions for the preparation of proustite single crystals are reported. For selecting these conditions temperature gradients in the crystallisation zone and in the melt, the rate of moving of the crystallisation front, the radial gradient, tube geometry, stabilisation of temperature, mechanisms of zone travelling, partial pressures were changed. – Differential-thermal, X-ray, and spectral-chemical analysis were applied to initial substances and final crystal bodies. To decrease the influence of spontaneous crystallisation an optimal temperature gradient was applied approaching maximum undercooling at the liquid-solid interface. – Optically transparent proustite crystals resulted. In the range from 1 to 12 μm they show 80% transparency. Microhardness was measured along the growth direction which deviated from the c-axis about 25°. |
