Enhancement of antiferromagnetic coupling in the quasi-one-dimensionalCa3Co2O6ferrimagnet

The magnetic coupling between quasi-one-dimensional ferromagnetic chains in ${\mathrm{Ca}}_3{\mathrm{Co}}_2{\mathrm{O}}_6$ oxide has been studied using magnetic measurements under quasihydrostatic pressure (P) up to 12 kbar. It is found that the low-temperature ferrimagnetic phase, resulting from the antiferromagnetic coupling of ferromagnetic chains, is stabilized under pressure. Both the critical field for the spin-flip transition of the linear chains ${(H}_{\mathrm{SF}})$ and the temperature $T^{*}$ where the long-range ferrimagnetic ordering sets in rise under pressure with the following rates: ${\mathrm{dH}}_{\mathrm{SF}}/dP\approx 135–155\mathrm{O}\mathrm{e}/\mathrm{k}\mathrm{b}\mathrm{a}\mathrm{r}$ and ${\mathrm{dT}}^{*}/dP\approx 0.073\mathrm{K}/\mathrm{k}\mathrm{b}\mathrm{a}\mathrm{r},$ respectively. We show that these variations can be accurately described in terms of the interchain bond-length compression.