Synthesis, single crystal growth and properties of $Sr_5Pb_3ZnO_{12}$
  The novel $Sr_5Pb_3ZnO_{12}$ oxide was synthesized by the solid-state reaction method. The crystal structure was studied by means of the powder x-ray diffraction Rietveld method and was found to be similar to 3 other previously known $Sr_5Pb_3MO_{12}$ compounds (M = Co, Ni, Cu). Crystals of several hundred microns in size of the new phase were grown in molten sodium chloride and imaged using confocal optical and scanning electron microscopy. Electrical properties were studied using the impedance spectroscopy technique. It was found that $Sr_5Pb_3ZnO_{12}$ is a dielectric material with rather high relative permittivity ($\epsilon_r$ = 22 at 300K) and with activation energy of the dielectric relaxation process $E_A$ = 0.80(4) eV. The heat capacity studies reveal the Debye temperature $\Theta_D$ = 324(1) K. 
Micha{\l} J. Winiarski and Natalia A. Szreder and Ryszard J.   Barczy\'nski and Tomasz Klimczuk
cond-mat.mtrl-sci