The lattice-vibration and transmissivity spectra show that the NYV crystal is a good laser host crystal, which provides a suitable crystal field for the active ions. Each unit cell has two molecules and a well defined cleavage plane, the ab plane. However, the crystals obtained were not of high quality. The DC conductivity strongly depends on the measuring voltage. No Ohmic regime exists in the current-voltage relation.
Ionic polarization occurs under high DC stresses.
Electrode reactions were also observed. The phenomena are related to the easy movement of ions along the z -axis of the KTP crystal. It was found that the excess amount of MgO and PbO, and the sintering temperature have great effect on the crystallographic properties of the ceramics. An analysis is made of the effect of the copper diffusion into semi-insulating undoped GaAs crystals on the intensity of the intrinsic luminescence. It is shown that the copper diffusion into semi-insulating undoped GaAs crystals could lead both to an increase and to a decrease in the intrinsic luminescence intensity.