Near-room-temperature ferrimagnetism and half-metallicity in disordered Ca1.5La0.5MnRuO6

The electron spin polarization on half-metallic double perovskites is usually conditioned to the ordered rock-salt arrangement of the transition-metal ions along the lattice. In this work, we investigate a polycrystalline sample of the Ca1.5La0.5MnRuO6 1 . 5 La 0 . 5 MnRuO 6 compound by employing x-ray powder diffraction, high-resolution transmission electron microscopy, x-ray absorption and magnetic circular dichroism at the Mn L 2 , 3 and Ru M 2 , 3 edges, magnetometry, electrical transport, and first-principles calculations in order to show that this is a fully disordered material exhibiting near-room-temperature ferrimagnetism and half-metallic conductivity, with significant intergrain tunneling magnetoresistance. These unprecedented results are compared to those of archetypical ordered double perovskites, and discussed in terms of the Mn and Ru valences and their orbital hybridization.