Stoichiometry dependence of oxygen anelastic relaxation in YBa2Cu3O7−χ and the orthorhombic-to-tetragonal phase transition

Internal friction and oxygen migration in NdxY1−xBa2CuOy (x=0.0–1.0) superconductors at low frequencies

“…This peak is associated with oxygen migration in the basal plane [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Fig.…”

“…Several groups have performed anelastic measurements employing different techniques to investigate oxygen migration (and defects) in YBa 2 Cu 3 O y (Y123) [1][2][3][4][5][6][7][8][9][10][11] and RBa 2 Cu 3 O y (R123, R = rare earth) [12][13][14][15]. Oxygen migration behavior in R123 is considerably influenced by the ionic size of the rare earth ion [12][13][14].…”

Internal friction of superconducting YBa2Cu3O6+x wires at 200 kHz under in situ heat treatment

“…Our measurements provide confirmation of the anelastic relaxation (both in modulus and internal friction) due to oxygen displacement between O(1)-O(5) sites and O-T transition for YBa 2 Cu 3 O 6+x . On the other hand, several workers [27][28][29][30][31][32] have reported another kind of internal friction peaks at lower temperatures (above room temperature) at various frequencies. If a plot could be made using the data of low-temperature peak which were confirmed by the results of Bonetti, Cannelli 31 , Mi 32 and by our work, we obtain that H = 1.1 ± 0.1 eV and τ 0 =1.7 × 10 -14 for linear relation with a wide range of frequencies, as a line (b) in Fig.…”

“…Ceder et al 38,39 reported a computer-simulated phase diagram of YBa 2 Cu 3 O 6+x versus temperature and oxy- 30 " " gen content, x. In addition of orthorhombic-to-tetragonal (O-T) phase transition, they have suggested the formation of the ordered phase with orthorhombic symmetry, named O phase in the moderate temperature range below about 600 K and in the oxygen content of x = 0.25-0.75.…”

“…The structure consists of a distributing filled oxygen-chain among empty ones; locally a double-cell structure derived from an orthorhombic YBCO. Bonetti et al 30 and Cannelli et al 31 has suggested that an IF peak (P 01 ) can be attributed to the O phase. On the other hand, several workers 27,32 has concluded the rising IF peaks after oxygen-release in YBCO is relaxation in a tetragonal phase which is more oxygen-defective than orthorhombic one.…”