First principles calculation to investigate the effect of Mn substitution on Cu site in CeCu3-x Mn x V4O12 (x = 0, 1, 2 and 3) system

Structural, electronic, elastic and magnetic properties of CeCu3-x Mn x V4O12 (x = 0, 1, 2 and 3) system have been carried out through DFT using GGA, GGA+U and HF potential. The investigation of structural optimization reveals that lattice parameters of the understudy system is reliable with the reported results and are increasing with the Mn substitution due to their greater atomic radii as compare to Cu atom. Both the cohesive energy and the enthalpy show that CeCu3V4O12 is the most thermodynamically stable among these compounds. When Mn is replaced by Cu in these compounds, not only it become semi-metals, but the host compound also changes from non-magnetic to anti-ferromagnetic and their electrical resistance provides further credence to their electronic behavior. Mechanical stability, anisotropy, and ductility are all demonstrated through the elastic characteristics of these compounds. Due to anti-ferromagnetic ductile nature of the Mn base compounds, it is expected that the compounds in the system may use for spintronic application and in magnetic cloaking devices.

Metamagnetic Behavior in a Quadruple Perovskite Oxide

A cubic quadruple perovskite oxide CeMn₃Cr₄O₁₂ has been synthesized under high-pressure and high-temperature conditions of 8 GPa and 1273 K. The X-ray absorption spectroscopy reveals that the Ce ions are in a trivalent state, as represented by the ionic model of Ce³⁺Mn³⁺₃Cr³⁺₄O₁₂. The magnetic study demonstrates three independent antiferromagnetic transitions attributed to Ce (∼10 K), Mn (46 K), and Cr (133 K) ions. Furthermore, a magnetic field-induced antiferromagnetic-to-ferromagnetic (metamagnetic) transition of Ce³⁺ 4f moments is observed at low temperatures below 20 K, exhibiting a rare example of metamagnetism in the Ce³⁺-oxides. This finding represents that the 3d-electron magnetic sublattices play a role in the metamagnetism of 4f-electron magnetic moments, demonstrating a new aspect of the 3d-4f complex electron systems.