For Sr 2-xLa xMnO 4, having a nearly two-dimensional electronic system of e g electrons, we have examined the crystallographic features of the charge-orbital-ordered (COO) and charge-exchange (CE)-type magnetic states for 0.40 ≤ x ≤ 0.55 by transmission electron microscopy. Incommensurate and commensurate longitudinal lattice modulations were found below ∼150 K for 0.47 ≤ x ≤ 0.51, while the cooling from the disordered tetragonal state resulted in the appearance of transverse modulations below T COO for 0.40 ≤ x ≤ 0.52. For 0.47 ≤ x ≤ 0.51, thus, the longitudinal and transverse modulations were present in both the lower-temperature region of the COO state and the CE-type magnetic state. In addition to these two states, the COO state for 0.40 ≤ x < 0.47 and 0.51 < x ≤ 0.52 accompanies only the transverse modulation and should be referred to as the orbital modulated state without a charge modulation.
|ジャーナル||Physical Review B - Condensed Matter and Materials Physics|
|出版ステータス||Published - 2011 7月 11|
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