Structural, magnetic and electrical transport properties of double perovskite Tb2MnCoO6

The double perovskite Tb2MnCoO6 and two simple perovskites TbMnO3 and TbCoO3 were synthesized by a solid sintering reaction method. The Rietveld refinement results based on the x-ray powder diffraction data identified all samples as orthorhombic perovskite structures with space group Pbnm (62). The lattice parameters of Tb2MnCoO6 were a = 5.278 (3) angstrom, b = 5.579 (4) angstrom, and c = 7.513 (4) angstrom with a cell volume = 221.2 (6) angstrom(3), Z = 2. Meta-magnetic behavior was observed near 92 K for Tb2MnCoO6, which was considered to be related to the coexistence of and competition between the ferromagnetic order and antiferromagnetic order. Temperature-dependent resistance (R-T) was also measured. Compared with TbCoO3 and TbMnO3, Tb2MnCoO6 is more conductive, with its activation energy reduced from 0.3062 eV for TbCoO3 (0.2754 eV for TbMnO3) to 0.1949 eV. The results reported here can assist in understanding the multiferroic physics mechanism of double perovskite materials.