TY - JOUR
T1 - Synthesis and structural properties of n = 1 Ruddlesden-Popper manganites Nd1-xCa1+xMnO4
AU - Nagai, T.
AU - Yamazaki, A.
AU - Kimoto, K.
AU - Matsui, Y.
N1 - Funding Information:
We thank T. Shibue, A. Sato, Y. Tomioka, T. Kimura, T. Asaka and C. Tsuruta for technical supports and helpful discussions. This work was supported by the Nanotechnology Support Project of the MEXT, Japan.
PY - 2008/4/3
Y1 - 2008/4/3
N2 - Polycrystalline samples of n = 1 Ruddlesden-Popper manganites Nd1-xCa1+xMnO4 (0.55 ≦ x ≦ 1.00) were synthesized by a solid-state reaction. X-ray diffraction (XRD) and electron diffraction (ED) measurements confirmed that the fundamental crystal structure at room temperature consists of three distorted K2NiF4-types: orthorhombic Bmab (64) phase in 0.55 ≦ x < 0.73, orthorhombic Acam (64) phase in 0.73 ≦ x < 0.85 and tetragonal I41/acd (142) phase in 0.85 ≦ x ≦ 1.00. Furthermore, in a whole range of 0.55 ≦ x ≦ 0.75, low-temperature magnetic and ED measurements revealed charge-orbital ordering (COO) states, which are accompanied by suppression of magnetization and structural modulations with q = (1 - x)a*. The COO transition temperatures are high with a maximum of ∼330 K at x = 0.67, and then higher than those in non-distorted n = 1 Ruddlesden-Popper manganites. The observations suggest that COO states are much stabilized by the distortion in the fundamental structures.
AB - Polycrystalline samples of n = 1 Ruddlesden-Popper manganites Nd1-xCa1+xMnO4 (0.55 ≦ x ≦ 1.00) were synthesized by a solid-state reaction. X-ray diffraction (XRD) and electron diffraction (ED) measurements confirmed that the fundamental crystal structure at room temperature consists of three distorted K2NiF4-types: orthorhombic Bmab (64) phase in 0.55 ≦ x < 0.73, orthorhombic Acam (64) phase in 0.73 ≦ x < 0.85 and tetragonal I41/acd (142) phase in 0.85 ≦ x ≦ 1.00. Furthermore, in a whole range of 0.55 ≦ x ≦ 0.75, low-temperature magnetic and ED measurements revealed charge-orbital ordering (COO) states, which are accompanied by suppression of magnetization and structural modulations with q = (1 - x)a*. The COO transition temperatures are high with a maximum of ∼330 K at x = 0.67, and then higher than those in non-distorted n = 1 Ruddlesden-Popper manganites. The observations suggest that COO states are much stabilized by the distortion in the fundamental structures.
KW - Crystal structure and symmetry
KW - Electronic states (localized)
KW - Scanning and transmission electron microscopy
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U2 - 10.1016/j.jallcom.2006.11.100
DO - 10.1016/j.jallcom.2006.11.100
M3 - Article
AN - SCOPUS:40149098840
VL - 453
SP - 247
EP - 252
JO - Journal of the Less-Common Metals
JF - Journal of the Less-Common Metals
SN - 0925-8388
IS - 1-2
ER -