MECHANICAL DOPING OF POLYCRYSTALLINE ALKALI-HALIDES WITH PB2+ IONS

It is shown that Pb2+ ions can be introduced into polycrystalline matr ices of NaCl, KCl, KBr, KI, and KCl0.5Br0.5 by mechanical treatment of powder mixtures of the relevant alkali halides (AH) with small quanti ties of PbCl2 or PbO (up to a few dozens of molar ppm). The comparison of the adsorption spectra of the above materials pressed into transpa rent pellets with those of conventionally Pb2+-doped AH single crystal s proves that due to mechanical stimulation the dopant enters into the AH matrix in the form of isolated Pb2+ ions substituting for the orig inal lattice cations. It is shown that mechanical treatment is also ef fective in preparing polycrystalline samples of some mixed alkali hali des like KCl0.5Br0.5. (C) 1996 Academic Press, Inc.