We performed thermal expansion and magnetostriction measurements of the perovskite-type Co oxides Sr1−xYx-CoO3−δ and Ca-doped Sr1−yY0.22CayCoO3−δ in high magnetic fields. Our experimental results show decrease of the magnetization of Sr1−xYxCoO3−δ upon cooling in the magnetic ordered phase, accompanied by considerable shrinkage of the crystal lattice. On the contrary, the application of magnetic fields causes the expansion of the lattice volume, resulting in positive magnetstriction. The strong relation between the ferromagnetic moment and the crystal lattice, suggested by our measurements, is consistent with the occurrence of a spin crossover in the magnetic ordered phase of these compounds.
ASJC Scopus subject areas
- Physics and Astronomy(all)