Datensatz

Zusammenfassung

Due to their high chemical stability at elevated temperatures combined with interesting electric and magnetic properties, perovskite-type rare earth orthochromites of composition RCrO3 (R = rare earth element) have potential applications as catalysts, electrolytes, fuel cells, spin valve materials, multiferroics, refractory ceramics, thermoelectric materials as well as gas-sensor devices. In this work, we present a short review of the electric and magnetic properties of rare earth orthochromites with light rare earths. Especially, we focus on recent results we obtained by investigating mixed phases Ce1-xEuxCrO3 (0 <= x <= 1) which were prepared as phase pure nano-powders (particle size 50-100 nm) employing the solution combustion method. Substitution with europium as an ion with the smaller radius size and a magnetic configuration different from that of Ce3+ has essential consequences for the structural and magnetic properties. CeCrO3 exhibits one of the highest antiferromagnetic ordering temperatures (similar to 257 K) among the rare earth orthochromite series. By substituting Ce with Eu the Neel temperature is continuously lowered, reaching similar to 182 K for EuCrO3. EuCrO3 orders itself with a G-type antiferromagnetic structure which we determined for the first time by elastic neutron scattering. The mixed phases Ce1-xEuxCrO3 exhibit puzzling electric and magnetic properties including magnetization reversal, exchange bias effect, and relaxor-type dielectric properties.