Enhanced magnetism and suppressed magnetoelastic coupling induced by electron doping in Ca1-x Y x MnReO6

The Ca2MnReO6 double perovskite is a spin-orbit-assisted Mott insulator with exotic magnetic properties, including a largely non-collinear Mn2+ spin arrangement and nearly orthogonal coupling between such spins and the much smaller Re 5d magnetic moments. Here, the electron-doped compound Ca1-x Y x MnReO6 (x = 0.1, 0.2 and 0.3) is reported and a detailed investigation is conducted for x = 0.3. Neutron and x-ray powder diffraction confirm that nearly full chemical order is maintained at the Mn and Re sites under the Y substitution at the Ca site. X-ray absorption measurements and an analysis of the Mn-O/Re-O bond distances show that the Mn oxidation state remains stable at +2 whereas Re is reduced upon doping. The electron doping increases the magnetic ordering temperature from T (c) = 121 to 150 K and also enhances significantly the ferromagnetic component of the Mn spins at the expense of the antiferromagnetic component at the base temperature (T = 3 K). The lattice parameter anomalies at T (c) observed in the parent compound are suppressed by the electron doping. The possible reasons for the enhanced magnetism and the suppressed magnetoelastic coupling in Ca1.7Y0.3MnReO6 are discussed.

Automated summary

The effect of electron doping on the magnetic and lattice parameters of Ca1-xYxMnReO6 compound is investigated. The results show that electron doping significantly enhances the ferromagnetic component of Mn spins, suppresses the antiferromagnetic component, and suppresses the lattice parameter anomalies observed in the parent compound. Electron doping also increases the magnetic ordering temperature.