SYNTHESIS, CRYSTAL-STRUCTURE AND MAGNETIC-PROPERTIES OF A(3)A'RUO6 (A=CA,SR, A'=LI,NA)

The compounds A(3)A'RuO6 (A = Ca, Sr; A' = Li, Na) have been synthesiz ed by solid state reactions and studied by X-ray powder diffraction an d magnetometry. They all adopt the K4CdCl6 (Sr4PtO6) structure with th e cations A' and Ru occupying the trigonal prismatic and octahedral si tes respectively. Infinite chains of octahedra and trigonal prisms sha ring faces run parallel to the c axis, the chains being separated by t he cations A (Ca, Sr). The validity of this description of the structu re is discussed in the light of magnetic susceptibility data which sug gest that these phases all transform to a magnetically ordered state i n the temperature range 70 < T/K < 120. Preliminary results of powder neutron diffraction experiments confirm the presence of long-range mag netic order in the low temperature phase. Copyright (C) 1997 Elsevier Science Ltd.