Theoretical studies of the electronic properties of ceramic materials

WY Ching - Journal of the American Ceramic Society, 1990 - Wiley Online Library
The first‐principles orthogonalized linear combination of atomic orbitals (OLCAO) method for
electronic structure studies has been applied to a variety of complex inorganic crystals. The …

Electron structure and vacancy properties and Al-substitution dependence of the positron lifetime in Y1: 2: 3 superconducting ceramics

J Zhang, F Liu, G Cheng, J Shang, J Liu, S Cao, Z Liu - Physics Letters A, 1995 - Elsevier
The positron lifetime spectra have been measured for an Al-substituted Y1: 2: 3
superconducting ceramic for the first time. The composition is YBa2Cu3− xAlxOy with x= 0 …

Positron annihilation spectroscopic studies on Nd-doped ceria

A Sachdeva, SV Chavan, A Goswami, AK Tyagi… - Journal of Solid State …, 2005 - Elsevier
We report a new result on the characterization of Nd-doped ceria, Ce1− xNdxO2− x/2 (x=
0.075–0.675) using positron lifetime spectroscopy (LTS) and coincidence Doppler …

Charge redistribution and properties of high-temperature superconductors

DI Khomskii, FV Kusmartsev - Physical Review B, 1992 - APS
We show that in high-T c superconductors (HTSC) with two groups of electrons (eg, holes in
CuO 2 planes and in a ''reservoir'') there should exist a charge redistribution with the …

The microstructure study of Co-doped YBCO system

L Liu, C Dong, J Zhang, J Li - Physica C: Superconductivity, 2002 - Elsevier
A series of YBa2Cu3− xCoxOy (x= 0–0.50) samples have been studied by means of SEM,
TEM, XRD and positron annihilation technology. Oxygen contents of the samples have been …

Positron annihilation on single crystals of

B Barbiellini, P Genoud, JY Henry, L Hoffmann… - Physical Review B, 1991 - APS
We present lifetime and two-dimensional angular correlation of (positron) annihilation
radiation (2D-ACAR) studies on YBa 2 Cu 3 O 7− x single crystals, both on metallic and on …

Suppression of superconductivity by the nonmagnetic ions and for the system: From dopant clusters to carrier localization

P Li, J Zhang, G Cao, C **g, S Cao - Physical Review B—Condensed Matter …, 2004 - APS
To clarify the suppressing mechanism of Zn and Al substitution on high-T c
superconductivity, positron annihilation experiment and simulated calculation are used to …

Pressure effect on the superconducting transition temperature of Tl2Can-1Ba2CunO2n+ 4-δ

JG Lin, K Matsuishi, YQ Wang, YY Xue, PH Hor… - Physica C …, 1991 - Elsevier
The pressure effect on the superconducting transition temperature (dT c/dP) has been
examined for the hole-high temperature superconductors (HTSCs) Tl 2 Ca n− 1 Ba 2 Cu n O …

Distorted local environment around Zn on Cu(2) sites in : An x-ray-absorption study

F Bridges, G Li, JB Boyce, T Claeson - Physical Review B, 1993 - APS
The substitution of Zn for Cu in YBa 2 Cu 3 O 7− δ (YBCO) causes a surprisingly large
suppression of the superconducting transition temperature. However, there has been some …

Theoretical calculation of electron-positron momentum density in YBa2Cu3O7− δ

S Massidda - Physica C: Superconductivity, 1990 - Elsevier
We present calculations of the electron-positron momentum density for the high-T c
superconductor YBa 2 Cu 3 O 7− δ for δ= 0 and for the insulating parent compound YBa 2 …