Crystal structure and magnetic properties of Gd8Mn3Sb19

Abstract

In this study, a novel magnetic semimetal compound, Gd8Mn3Sb19, was synthesized successfully via high-temperature solid-state reaction. The crystal structure of Gd8Mn3Sb19 was determined using both single crystal and powder X-ray diffraction techniques, revealing a non-centrosymmetric orthorhombic space group, Pmn21 (No. 31). The Sb atoms in Gd8Mn3Sb19 form five-atom-wide Sb57− ribbons, narrower three-atom-wide Sb35− ribbons, and single Sb3− anions. On the other hand, both Gd3+ and Mn2+ ions form the distorted Gd3 and Mn3 triangular lattices, respectively. The magnetic measurements suggest the complex magnetic interactions contributed by both Gd3+ and Mn2+ ions. A sharp peak observed in the magnetic susceptibility plot at approximately 25 K corresponds to the antiferromagnetic-type transition in Gd8Mn3Sb19. Furthermore, the magnetic measurements along different directions indicate the strong magnetic anisotropy present in Gd8Mn3Sb19, which is likely due to the complex magnetic interactions arising from the existence of Gd and Mn ions. Finally, the electrical resistivity measurements of Gd8Mn3Sb19 indicate semimetallic behavior with a positive magnetoresistance.