New tetragonal derivatives of cubic NaZn13-type structure: RNi6Si6 compounds, crystal structure and magnetic ordering (R=Y, La, Ce, Sm, Gd–Yb)

Novel RNi6Si6 compounds adopt the new CeNi6Si6-type structure for R=La–Ce (tP52, space group P4/nbm N 125-1) and new YNi6Si6-type structure for R=Y, Sm, Gd–Yb (tP52, space group P4¯b2N 117) that are tetragonal derivative of NaZn13-type structure, like LaCo9Si4-type.The CeNi6Si6, GdNi6Si6, TbNi6Si6, DyNi6Si6 and HoNi6Si6 compounds are Curie–Weiss paramagnets down to ~30K, and do not order magnetically down to 5K. However, the inverse …