This paper reports on an ultrasonic study at 130 kHz region in melt-textured Nd123, i.e. NdBa2Cu3O7-δ with different oxygen levels, i.e. δ = 0, 0.2, 0.4, 0.6, 1. Three ultrasonic attenuation peaks were identified, which were related to oxygen levels in the material. An ultrasonic attenuation peak in the 360 K region was found at higher oxygen levels, i.e. δ = 0.2, 0.4, and appeared to be a characteristic of the orthorhombic phase of the material. An ultrasonic attenuation peak in the 160 K region occurred at lower oxygen levels, i.e. δ = 0.4, 0.6, while a peak close to 320 K was found in deoxygenated Nd123. All ultrasonic attenuation peaks showed the characteristics of structural changes. This proposal is supported by ultrasonic velocity measurements which displayed discontinuities at the corresponding temperatures.
|ジャーナル||Materials Science and Engineering B: Solid-State Materials for Advanced Technology|
|出版ステータス||Published - 1999 10月 29|
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