Paramagnetic nature of the layered cobalt dioxide with a double rocksalt-type layer

Ikedo, Yutaka; Sugiyama, Jun; Nozaki, Hiroshi; Russo, Peter L.; Andreica, Daniel; Amato, Alex; Månsson, Martin; Shizuya, Mitsuyuki; Isobe, Masaaki; Takayama-Muromachi, Eiji

doi:10.1016/j.physb.2008.11.113

Paramagnetic nature of the layered cobalt dioxide with a double rocksalt-type layer

Ikedo Y, Sugiyama J, Nozaki H, Russo PL, Andreica D, Amato A, Månsson M, Shizuya M, Isobe M & Takayama-Muromachi E

Citation

Ikedo, Y., Sugiyama, J., Nozaki, H., Russo, P. L., Andreica, D., Amato, A., … Takayama-Muromachi, E. (2009). Paramagnetic nature of the layered cobalt dioxide with a double rocksalt-type layer. Physica B: Condensed Matter, 404(5-7), 607-610. https://doi.org/10.1016/j.physb.2008.11.113

Persistent URL https://www.dora.lib4ri.ch/psi/islandora/object/psi:17315

In order to elucidate the origin of a small magnetic anomaly at T_m = 13 K in [Ca_0.85OH]_1.16^RS[CoO₂], we have measured μ⁺SR spectra down to 1.8 K using a pressed powder sample synthesized by a high-pressure technique. The ZF-μ⁺SR spectrum at 1.8 K is well fitted by a damped precessing signal caused by a formation of μ⁺-OH bond together with an exponential relaxation function due to a disordered magnetic field. The volume fraction of the former signal is approximately 80%, whereas the latter is ∼ 20 %. Furthermore, all the major μ⁺SR parameters, such as the two asymmetries (A_μOH and A_e), the precession frequency due to the μ⁺-OH bond, and its Gaussian relaxation rate are independent of T both above and below T_m. This is a clear indication that T_m is not magnetic order but structural and/or electronic in origin.