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Raman scattering in MBa2Cu3O7 with M=Y, Eu, and Gd: Effect of 18O substitution and oxygen vacancies on the Cu-O vibrational modes

Physical Review B (Impact Factor: 3.66). 01/1987; 36:8320-8324. DOI: 10.1103/PhysRevB.36.8320

ABSTRACT We have studied the Cu-O vibrations in the MBa2Cu3O7 systems with M=Y, Eu and Gd by Raman spectroscopy. The observed Raman features are similar in the three systems. The four Raman bands in the 300-700 cm-1 frequency region exhibit isotopic shifts upon 18O substitution implying that these modes involve oxygen vibrations. In oxygen-deficient YBa2Cu3O7-delta samples prepared in the range 0

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