TY - JOUR
T1 - Structural phase transitions and the effect on Pr anomalous ordering for the PrBa2-xLaxCu3O7+y system
AU - Ku, H. C.
AU - Luo, H. M.
AU - Chi, Y. P.
AU - Lin, B. N.
AU - Hsu, Y. Y.
AU - Lin, C. H.
AU - Kao, H. C.I.
N1 - Funding Information:
The research is supported by NSC88-2112-M007-003 and -033.
PY - 2000/6/1
Y1 - 2000/6/1
N2 - Complex crystal symmetry variation is observed for the oxygenated PrBa2-xLaxCu3O7+y system (0≤x≤1, -0.12≤y≤0.39). Powder X-ray Rietveld analysis indicates that the crystal structure changes from the PrBa2Cu3O7 or CuBa2PrCu2O7 1212C-type (C for chain) orthorhombic O(I)-phase (space group Pmmm) to 1212-type tetragonal T-phase (P4/mmm) around x = 0.45, and then to a new 1212-type of orthorhombic O(II)-phase (Cmmm) around x = 0.65. However, regardless of the structural change, anomalous Pr ordering temperature TN(Pr) decreases monotonically from 18 K for PrBa2Cu3O6.88 to 2.8 K for PrBa1.3La0.7Cu3O7.24. The increasing Pr-O bond length with decreasing TN indicates that Pr ordering is closely correlated with the wave function overlap between Pr-4f orbital and O-2pπ orbital in the CuO2 bi-layers.
AB - Complex crystal symmetry variation is observed for the oxygenated PrBa2-xLaxCu3O7+y system (0≤x≤1, -0.12≤y≤0.39). Powder X-ray Rietveld analysis indicates that the crystal structure changes from the PrBa2Cu3O7 or CuBa2PrCu2O7 1212C-type (C for chain) orthorhombic O(I)-phase (space group Pmmm) to 1212-type tetragonal T-phase (P4/mmm) around x = 0.45, and then to a new 1212-type of orthorhombic O(II)-phase (Cmmm) around x = 0.65. However, regardless of the structural change, anomalous Pr ordering temperature TN(Pr) decreases monotonically from 18 K for PrBa2Cu3O6.88 to 2.8 K for PrBa1.3La0.7Cu3O7.24. The increasing Pr-O bond length with decreasing TN indicates that Pr ordering is closely correlated with the wave function overlap between Pr-4f orbital and O-2pπ orbital in the CuO2 bi-layers.
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U2 - 10.1016/S0921-4526(99)00784-X
DO - 10.1016/S0921-4526(99)00784-X
M3 - Conference article
AN - SCOPUS:0033876291
SN - 0921-4526
VL - 281-282
SP - 892
EP - 893
JO - Physica B: Condensed Matter
JF - Physica B: Condensed Matter
T2 - Yamada Conference LI - The International Conference on Strongly Correlated Electron Systems (SCES '99)
Y2 - 24 August 1999 through 28 August 1999
ER -