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arXiv · 1310.8548

Novel dielectric anomalies due to spin-chains above and below Neel temperature in Ca3Co2O6

Tathamay Basu·Kartik K Iyer·Kiran Singh·E. V. Sampathkumaran
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Abstract

We bring out novel dielectric behavior of a spin-chain compound, Ca3Co2O6, undergoing Neel order at (T_N=) 24 K. It is found that the virgin curve in the plot of isothermal dielectric constant versus magnetic-field lies outside the 'butterfly-shaped' envelope curve well below T_N (e.g., 2.6 K), with a signature of a partial arrest of the high-field magnetoelectric ME) phase in zero-field after travelling through magnetic-field-induced magnetic transitions. This behavior is in contrast to that observed in the isothermal magnetization data. Thus, this work brings out a novel case for 'phase-coexistence phenomenon' due to ME coupling. Another strange finding is that there is a weak, but a broad, peak in dielectric constant around 85 - 115 K well above T_N, attributable to incipient spin-chain magnetic ordering. This finding should inspire further work to study ME coupling on artificial assemblies of magnetic chains, also keeping in mind miniaturization required for possible applications.

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Tathamay Basu, Kartik K Iyer, Kiran Singh, E. V. Sampathkumaran. 2013-10-31. Novel dielectric anomalies due to spin-chains above and below Neel temperature in Ca3Co2O6. https://arxiv.org/abs/1310.8548

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