MORE COMPOUNDS OF THE BA(17)LN(16)ZN(8)PT(4)O(57) TYPE WITH LN=DY, HO, ER, Y

Single crystals of Ba17Dy16Zn8Pt4O57 (I), Ba17Ho16Zn8Pt4O57 (II), Ba17 E16Zn8Pt4O57 (III) and Ba17Y16Zn8Pt4O57 (IV) have been prepared by hig h temperature reactions using platinum crucibles. X-ray investigations led to tetragonal symmetry, space group C-4h(5)-I4/m, (I) - (IV): a = 22.905(1), 22.840(1), 22.795(1), 22.848(1) Angstrom and c = 5.728(1), 5.722(1), 5.700(1), 5.709(1) Angstrom, Z = 2. The crystal structure i s characterized by small square, medium-sized quadrangular and large r ectangular tunnels, which are filled by oxygen, barium and zinc. The p olyhedra network is discussed with respect to the network of compounds of the Ba13Dy8Zn4Pt4O37 type.