Magnetic Properties of Spinel Cobaltite A Co₂O₄ (A=Zn and Li)

Abstract:

We synthesized polycrystals of cobaltite spinels LiCo₂O₄, ZnCo₂O₄, and their mixed crystal (Li_1-xZn_x)Co₂O₄, and performed the magnetic susceptibility and specific heat measurements. LiCo₂O₄ with the Weiss temperature Θ_W ~ -114 K exhibits an antiferromagnetic transition at T_N ~ 30 K. On the other hand, ZnCo₂O₄ with the Weiss temperature Θ_W ~ -90 K exhibits the absence of magnetic phase transition down to low temperature (2 K), indicating the presence of strong frustration. Taking into account the absence of magnetic phase transition in the orbital-degenerate ZnCo₂O₄, it is suggested that the antiferromagnetic transition in the charge-orbital-degenerate LiCo₂O₄ is driven by the charge degree of freedom. Furthermore, the magnetic properties of (Li_1-xZn_x)Co₂O₄ suggest that the antiferromagnetic transition in LiCo₂O₄ is sensitively suppressed by diluting the charge degeneracy.

• Periodical: Solid State Phenomena (Volume 257)
• Pages: 115-118
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.257.115
• Online since: October 2016
• Authors: Ryota Murai, Minoru Maeda, Kouichi Takase, Yoshiki Takano, Tadataka Watanabe*
• Keywords: Cobaltite, Electronic Degree of Freedom, Geometrical Frustration, Spinel

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