Reduced magnetic disorder at low temperature in Ca3Co2O6 via zinc substitution
Department or Administrative Unit
The compound Ca3Co2O6 undergoes a transition into a spin-density wave (SDW) state near 24 K. Below ∼10 K, this unstable SDW state coexists with a nearly- degenerate commensurate antiferromagnetic state as well as short-range magnetic order. Clear signatures of this strong magnetic disorder have been observed in the response of entropy to changing magnetic field and temperature. We performed a calorimetry study of Ca3Co2O6 and Ca3Co1.9Zn0.1O6 in order to compare their entropic responses at low temperature. Our results for Ca3Co2O6 reveal that ΔS(T, H) ≡ S(T, H)−S(T, H = 0) increases as either temperature or magnetic field increase. In contrast, ΔS data for Ca3Co1.9Zn0.1O6 were relatively unresponsive to changes in temperature or field, suggesting that Zn substitution may reduce the low-temperature magnetic disorder observed in Ca3Co2O6. These results are discussed within the context of two cases (Ca3Co2O6 under applied pressure and Ca2.75R0.25Co2O6 (R = Dy, Lu)) in which a single magnetic ground state is stabilised.
White, B. D., Mantilla, A. B. C., & Jesenovec, J. (2019). Reduced magnetic disorder at low temperature in Ca3Co2O6 via zinc substitution. Philosophical Magazine, 100(10), 1226–1243. https://doi.org/10.1080/14786435.2019.1708497