Influence of ionic substitution on the magnetic behaviour of Y2Cu2O5

Abstract

The influence of the substitution of Cu or O by various elements on the magnetic properties of Y₂Cu₂O₅ has been studied. The substitution of Cu by metal ions with unpaired d electrons (M = Co²⁺, Ni²⁺) makes the superexchange in Cu₂O₈ chains stronger, but the substitution by those metal ions without unpaired electrons (M = Zn²⁺, Mg²⁺) makes the superexchange weaker. The substitution of O by S also makes the superexchange weaker. Magnetic properties of Y₂Cu_{2 –x}M_xO₅ and Y₂Cu₂O_{5 –y}S_y were studied between 77 K and room temperature. Samples were characterized by X-ray diffraction (XRD), electron paramagnetic resonance (EPR) and thermal gravimetry (TG).