Effect of ageing on optical and thermal properties of YBa2Cu3O7–δ

• Published in: International journal of materials research Vol. 98; no. 7; pp. 569 - 573
• Main Authors: Nikolic, Pantelija M., Vujatovic, Stevan S., Paraskevopoulos, Konstantinos M., Zorbas, Kostas T., Savic, Slavica M., Nikolic, Maria Vesna, Aleksic, Obrad S., Ristic, Momcilo M.
• Format: Journal Article
• Language: English
• Published: Munich De Gruyter 01.07.2007; Hanser
• Subjects: Ageing; Applied sciences; Exact sciences and technology; Infrared spectroscopy; Metals. Metallurgy; Photoacoustic spectroscopy; YBa; δ; Thermal properties; Infrared spectrometry; Infrared spectroscopy; YBa2Cu3Ο7-δ; Optical properties; Ageing; Photoacoustic spectroscopy
• ISSN: 1862-5282; 2195-8556
• DOI: 10.3139/146.101511

Photoacoustic phase and amplitude spectra of YBa Cu – δ samples synthesised 18 years ago were measured and numerically analysed. The value of thermal diffusivity obtained on the aged samples was lower than the values obtained for fresh samples. Far infrared spectra of YBa Cu – δ samples synthesised 18 years ago were recorded and analysed enabling determination of reflectivity peak phonon frequencies present at room temperature. X-ray diffraction analysis and far infrared reflectivity measurements enabled determination of a slight change of the oxygen content with time. The YBa Cu – δ samples synthesised 18 years ago still remained superconducting, which was confirmed by resistivity measurements of the samples between 50 K and room temperature where the critical temperature was reduced from 93 to 73 K. Atomic force microscopy, scanning electron microscopy and energy dispersive X-ray microanalytical measurements were also performed confirming the composition of the sample.