Abstract: A method of growing mixed crystals having at least two lattice sites each having a different number of adjacent oxygen ions from melts of oxidic multi-component systems, homogeneous mixed crystals being grown such that the cations intended to occupy the first lattice site having the highest number of adjacent oxygen ions and to occupy the second lattice site having the next lowest number of adjacent oxygen ions are chosen such that the ratio of the bond length of the cations in the first lattice site to the bond length of the cations in the second lattice site is in the range from 0.7 to 1.5.

Abstract: A method of growing mixed crystals having two lattice sites, each of which having a different number of adjoining oxygen ions, from melts of oxidic multicomponent systems, homogeneous mixed crystals being grown in such a manner that the cations which are to populate the first lattice site having the largest number of adjoining oxygen ions and the cations which are to populate the second lattice site having the second largest number of adjoining oxygen ions are selected in such a manner that the ratio between the average ion radii of the cations on the first lattice site and the average ion radii of the cations on the second lattice site ranges from 2.2 to 2.5.