Temperature and composition phase diagram in the iron-based ladder compounds Ba1−xCsxFe2Se3

We investigated the iron-based ladder compounds (Ba,Cs)Fe2Se3. Their parent compounds BaFe2Se3 and CsFe2Se3 have different space groups, formal valences of Fe, and magnetic structures. Electrical resistivity, specific heat, magnetic susceptibility, x-ray diffraction, and powder neutron diffraction measurements were conducted to obtain a temperature and composition phase diagram of this system. Block magnetism observed in BaFe2Se3 is drastically suppressed with Cs doping. In contrast, stripe magnetism observed in CsFe2Se3 is not so fragile against Ba doping. A new type of magnetic structure appears in intermediate compositions, which is similar to stripe magnetism of CsFe2Se3, but interladder spin configuration is different. Intermediate compounds show insulating behavior, nevertheless a finite T-linear contribution in specific heat was obtained at low temperatures. ©2015 American Physical Society

Keywords

Phase transformations, X-ray diffraction, Neutron diffraction, Phase diagrams, Magnetism, Specific heat, Spin

Citation

Hawai, T., Nambu, Y., Ohgushi, K., Du, F., Hirata, Y., Avdeev, M., Uwatoko, Y., Sekine, Y., Fukazawa, H., Ma, J., Chi, S., Ueda, Y., Yoshizawa, H., & Sato, T. J. (2015). Temperature and composition phase diagram in the iron-based ladder compounds Ba1−xCsxFe2Se3. Physical Review B, 91(18), 184416. doi:10.1103/PhysRevB.91.184416