The effect of Zn substitution on the state of oxygen deficiency and hole concentration in Y1-xCaxBa2(Cu1-yZny)3O7-d

TL;DR

This study examines how zinc substitution affects oxygen deficiency and hole concentration in Y1-xCaxBa2(Cu1-yZny)3O7-delta, revealing systematic changes in oxygen content and hole doping levels due to Zn incorporation.

Contribution

It provides new insights into the impact of Zn substitution on oxygen deficiency and hole concentration in high-temperature superconductor compounds.

Findings

Zn substitution causes increased oxygen deficiency.

Hole content p varies systematically with Zn substitution.

Annealing conditions influence oxygen content in Zn-substituted samples.

Abstract

We have investigated the effect of Zn substitution on the hole content, p, and the oxygen deficiency, d, for a series of high-quality crystalline c-axis oriented thin films and polycrystalline Y1-xCaxBa2(Cu1-yZny)3O7-delta compounds over a wide range of composition (x, y, and delta). p was determined from the room-temperature thermopower, S[290K]. When annealed at a given temperature and oxygen partial pressure, a small but systematic variation in S[290K] was observed with Zn, for all the samples. From the analysis of the temperature derivative of resistivity, drho/dT, at 300K, which varies almost linearly with p, irrespective of the composition of the sample, and the thermo-gravimetric analysis (TGA), we have found that annealing under identical conditions makes the Zn-substituted compounds somewhat more oxygen deficient compared to the Zn-free ones.