Induction of Colossal Magnetoresistance in the Double Perovskite Sr2CoMoO6

M.C. VIOLA; M.J. MARTÍNEZ-LOPE; J.A. ALONSO; P. VELASCO; J.L. MARTÍNEZ; J.C. PEDREGOSA; R.E. CARBONIO; M.T. FERNÁNDEZ-DÍAZ

American Chemical Society

Año: 2002 vol. 14 p. 812 - 812

p style="TEXT-ALIGN: justify; LINE-HEIGHT: 200%; MARGIN: 0cm 0cm 0pt; TEXT-AUTOSPACE: ; mso-layout-grid-align: none" class="MsoNormal">Sr2CoMoO6 perovskite has been prepared in polycrystalline form by thermal treatment, in air, of previously decomposed citrate precursors. This material has been studied by X-ray (XRD) and neutron powder diffraction (NPD), thermal analysis, and magnetic, magnetotransport, and Hall effect measurements. At room temperature, the crystal structure is tetragonal with a space group I4/m, with a= 5.56503(5) and c =7.94810(8) Å. The crystal contains alternating CoO6 and MoO6 octahedra, tilted by 6.8° in the basal ab plane. Magnetic measurements indicate an antiferromagnetic ordering below TN= 37 K. As prepared, the sample is an electrical insulator. The topotactic reduction of the stoichiometric sample, in H2/N2 flows, leads to oxygen-deficient doub