Transmission electron microscope studies of the crystal structure of Y₂Cu₂O₅and the nature of nonperiodic planar defects in Y₂Cu₂O₅

Abstract

An account is given of transmission electron microscope studies of the crystal structure of Y2Cu2O5 discovered within samples of YBa2Cu3O7-x and Y1.85Sr0.15CuO4- delta ceramic compounds. Conventional and high-resolution electron microscope investigations confirmed that Y2Cu2O5 is isostructural with Ho2Cu2O5 and has a space group P21nb with lattice parameters a=1.247 nm, b=1.081 nm and c=0.3495 nm. The nature of planar defects discovered within the crystallites of Y2Cu2O5 is discussed. It is proposed that small amounts of barium that do not react to form a solid solution with Y2Cu2O5 segregate to the lines of defects. The displacement vector for the planar defects was found to be 1/2(014).

Transmission electron microscopy analysis of a coated conductor produced by chemical deposition methods

“…One frequently encountered secondary phase is the semiconductor Y 2 Cu 2 O 5 . In-depth XRD and TEM studies have elucidated the structural information and revealed the microstructure of Y 2 Cu 2 O 5 [18,19]. In Fig.…”

Incommensurate Modulated Structure and Planar Faults of a Phase within Y2—xCaxCu2O5Material with x = 0.1, 0.2 and 0.4

“…The crystal structure of Y 2 Cu 2 O 5 is orthorhombic with lattice parameters a 0 = 1.080 nm, b 0 = 0.349 nm and c 0 = 1.245 nm, space group Pna2 1 . Planar defects within this material were first reported by BabaKishi et al [7]. Single crystal Y 2 Cu 2 O 5 has been grown successfully using the flux method [8].…”

“…The measured angles between each zone axis represented by going from Fig. 1A to F [7]), and cannot be indexed based on the lattice parameters for Y 2 Cu 2 O 5 , i.e. a = 1.08 nm, b = 0.35 nm and c = 1.23 nm.…”

“…The crystal structure of Y 2 Cu 2 O 5 has been studied as a member of the family of Ln 2 Cu 2 O 5 (Ln = Ho, In, F F F) by X-ray diffraction [3,4], powder neutron diffraction [5,6] and transmission electron microscopy [7]. The crystal structure of Y 2 Cu 2 O 5 is orthorhombic with lattice parameters a 0 = 1.080 nm, b 0 = 0.349 nm and c 0 = 1.245 nm, space group Pna2 1 .…”

Magnetic properties of Y2CU205 and Y1.9Ca0.1Cu205

“…0 5 G), in which the susceptibility turns negative, indicating a superconducting transition. Crystal structure studies on Y2Cu205 have also been reported [5]. In this letter, we report results on the magnetic properties of Y2Cu2Os and Y1.9Cao.lCU2Os, so as to determine the effect of Ca doping on the magnetic properties.…”