Single crystals of hexagonal RMnO3 (R=Y, Yb, and Lu), where Mn ions form the triangular lattice, were investigated, focusing on their dielectric/magnetic anomalies as well as geometrical spin frustration. It is found that the ratio of a Weiss temperature to TN is ∼10 in RMnO3, indicating the dominant role of strong geometrical frustration. The effect of geometrical frustration also appears in specific heat, which shows a presence of a substantial amount of residual magnetic contribution below TN, indicating that a part of the spins are still fluctuating at T≪TN. It is also found that the dielectric anomaly at TN is strongly anisotropic, suggesting a unique correlation between magnetism and dielectric properties in these compounds.
|ジャーナル||Physical Review B - Condensed Matter and Materials Physics|
|出版ステータス||Published - 2001 9月 1|
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