The mechanical and structural properties of Y1Ba2Cu3O7-x superconductors

• Published in: Journal of materials science Vol. 29; no. 2; pp. 482 - 485
• Main Authors: ALNASER, W. E, ZEIN, M. M, KHAN, M. N, AL-DALLAL, S. S, MEMON, A. M, AL-OTHMAN, M. J
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.01.1994
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cuprates superconductors (high tc and insulating parent compounds); Exact sciences and technology; High-Tc compounds; Inorganic compounds; Mechanical and acoustical properties, elasticity, and ultrasonic attenuation; Physics; Properties of type I and type II superconductors; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Superconductivity; Water, oxides, hydroxides, peroxides; Y-based cuprates; Temperature dependence; Inorganic compounds; Transition element compounds; Ultrasonic waves; Perovskites; Infrared spectra; Experimental study; Relaxation; Barium oxides; High-Tc superconductors; Orthorhombic lattices; Attenuation; Temperature range 65-273 K; Quaternary compounds; Copper oxides; Yttrium oxides; Electric conductivity; Crystal structure
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/BF01162511

Mechanical losses spectroscopy of two superconducting YBa2Cu3O7-x samples (Tc = 93 K) measured at 5, 10, 20 and 30 MHz revealed four peaks. As the frequency of measurement was increased, the peaks shifted to higher temperatures. The relaxation process was found to have an activation enthalpy of 0.188, 0.092, 0.209 and 0.314 eV with an attempt frequency equal to 2.46 x 10 exp(15), 5.95 x 10 exp(10), 1.64 x 10 exp(14), and 7.82 x 10 exp(13) Hz for P1, P2, P3 and P4 peaks, respectively. The mechanism responsible for these relaxation peaks is discussed. The infrared spectra of some of these compounds provide evidence for oxygen rearrangement on going from tetragonal to orthorhombic phase. XRD analysis shows that these compounds correspond to a single phase which is an orthorhombic perovskite structure. 15 refs.