Hole doping into the metastable LuMnO3 perovskite

Single-phase samples of (Lu1−xCax)MnO3 of the orthorhombic perovskite structure have been realized through solid-state synthesis under high pressures for the Ca contents 0≤x≤0.30≤x≤0.3 and at ambient pressure for x=0.5x=0.5. The samples were characterized for basic structural, magnetic and transport properties with respect to xx. With increasing xx, Mn is gradually oxidized and the cooperative Jahn–Teller distortion appears to diminish. Increasing the concentration of MnIV at the expense of MnIII was found to enhance the ferromagnetic-like interactions and decrease electrical resistivity. Efforts to dope the orthorhombic LuMnO3 perovskite phase with holes by other means than the aliovalent CaII-for- LuIII substitution turned out to be infeasible: the larger alkaline earth element, Sr, did not enter the phase and high-pressure oxygenation treatments resulted in stabilization of the Lu2Mn2O7 pyrochlore phase.