Abstract: In order to prevent crystal seeds with retrograde solubility from dissolving in the hydrothermal growing solution at the beginning of the growing process, and to protect the finished crystal at the end of the growing process, and in order to reach the thermodynamic growth equilibrium as soon as possible, the proposal is put forward that the growing solution be prepared, pre-saturated and pre-heated to a temperature close to saturation temperature outside of the growing tank, and that, for the growing process proper, the hot growing solution be added to the pre-heated growing tank provided with crystal seeds, where it should be further heated to a temperature at which the crystals start growing, and, further, that the hot growing solution be quickly removed from the growing tank as soon as the growing process has been completed.

Abstract: In order to prevent crystal seeds with retrograde solubility from dissolving in the hydrothermal growing solution at the beginning of the growing process, and to protect the finished crystal at the end of the growing process, and in order to reach the thermodynamic growth equilibrium as soon as possible, the proposal is put forward that the growing solution be prepared, pre-saturated and pre-heated to a temperature close to saturation temperature outside of the growing tank, and that, for the growing process proper, the hot growing solution be added to the pre-heated growing tank provided with crystal seeds, where it should be further heated to a temperature at which the crystals start growing, and, further, that the hot growing solution be quickly removed from the growing tank as soon as the growing process has been completed.

Abstract: Individual single crystal elements stacked one above the other are aligned with their optical (Z) axes parallel to each other, and are provided with contact electrodes on opposite surfaces normal to their electrical (X) axes. Contact electrodes of the same polarity are conductively connected by two bridge electrodes that are applied to opposite sides of the assembled stack of individual crystal elements in the form of a conductive coating, and are provided with a lead leaving the sensor element. Contact electrodes of the opposite polarity are recessed in the vicinity of the bridge electrode serve the other polarity.