Ferromagnetism and metallicity in Sm0.2Ca0.8Mn1-xRuxO3 (x=0-0.08): Interplay between Ru doping and hydrostatic pressure - art. no. 224415

摘要

Magnetic properties of Sm0.2Ca0.8Mn1-xRuxO3 (x=0, 0.04, and 0.08) are investigated in the temperature range 4.2-240 K, external magnetic fields up to 15 kOe and hydrostatic pressure up to 12 kbar. Transport properties of Sm0.2Ca0.8Mn0.92Ru0.08O3 are also investigated in the temperature range 77-280 K and under pressure up to 10 kbar. It is found that for a pristine phase (x=0), hydrostatic pressure increases the ferromagnetic domains embedded in an antiferromagnetic matrix, and slightly decreases the Neel temperature. The effect of pressure on the magnetic interactions depends upon Ru doping. For Sm0.2Ca0.8Mn0.96Ru0.04O3 an applied pressure decreases both Curie and Neel temperatures, but enhances the ferromagnetic fraction. In the case of Sm0.2Ca0.8Mn0.92Ru0.08O3 an applied pressure suppresses the ferromagnetic interactions and surprisingly increases the resistivity. To the best of our knowledge this is the first time that such an effect was observed in perovskites. All of the above observations are discussed in the context of phase separation. [References: 23]