Pressure effect on magnetic transitions in one-dimensional Ca3Co2O6

In Ca3Co2O6 with one-dimensional ferromagnetic Co chains, magnetization measurements have been performed under pressure up to 1.40 GPa. From the temperature and magnetic field dependences of magnetization, we revealed the magnetic phase diagram of Ca3Co2O6. As pressure is applied to the sample, the magnetic ordering temperature T-c1 increases linearly at the similar rate in all fields up to 5.0 T. The spin-flip temperature T-flip and the spin-flip field H-flip show the linear pressure dependence. These results indicate that the lattice compression enhances a nearest-neighbor antiferromagnetic interaction J(1) between chains. By applying pressure, the ferrimagnetic ordering temperature T-c2 increases in 0.5 T, suggesting the enhancement of a second-nearest-neighbor ferromagnetic interaction J(2). (C) 2003 Elsevier B. V. All rights reserved.