Cation distribution and ferromagnetic exchange in the YMn0.5Co0.5O3YMn0.5Co0.5O3 perovskite investigated by neutron powder diffraction

The synthesis and characterization of a polycrystalline YMn0.5Co0.5O3-δYMn0.5Co0.5O3-δ sample are reported. The oxygen-content, determined by the thermogravimetric method from complete reduction in flowing 5%H2/N25%H2/N2, shows some oxygen deficiency leading to the composition YMn0.5Co0.5O2.87YMn0.5Co0.5O2.87. Neutron powder diffraction shows some cation ordering at the six-coordinate site resulting in a monoclinic unit cell with a=5.241(1)a=5.241(1), b=5.594(1)b=5.594(1), c=7.468(1)c=7.468(1) and, β∼90∘β∼90∘ (space group P21/nP21/n) at 290 K. The sample undergoes a transition to a ferromagnetic phase at Tc∼67K, with an ordered magnetic moment of 2.72(2) μBμB per formula unit aligned along [0 0 1].

Thermogravimetric curves of hydrogen reduction of YMn0.5Co0.5O3YMn0.5Co0.5O3 (upper) and YMn0.5Ni0.5O3YMn0.5Ni0.5O3 (lower) in 5%H2/N25%H2/N2 flow. Heating rate is 2∘C/min2∘C/min.Figure optionsDownload full-size imageDownload as PowerPoint slide