Intergranular properties of uniaxially pressed YBa2Cu3O7-δ ceramic samples

Author(s)

I. García-Fornaris ^[1] ; E. Govea- Alcaide ^[2] ; P. Muné ^[3] ; R.F. Jardim ^[4]

Affiliation

^[1] Universidad de Granma. Departamento de Ciencias Básicas - Cuba

^[2] Universidade de São Paulo. Instituto de Física - Brasil

^[3] Universidad de Oriente. Departamento de Física - Cuba

^[4] Universidade de São Paulo. Instituto de Física - Brasil

• Document type: Journal article
• Source: REVISTA MEXICANA DE FISICA; v. 56, n. 1, p. 40-43, 2010-02-00.

Abstract

We performed measurements of electrical resistivity as a function of temperature, ρ(Τ), in polycrystalline samples of YBa2Cu3O7-δ (Y-123) subjected to different uniaxial compacting pressures. We observed by using X-ray diffractometry that samples have a very similar composition. Most of the identified peaks are related to the superconducting Y-123 phase. Also, from the X-ray diffraction patterns performed, in powder and pellet samples, we estimated the Lotgering factor along the (00l) direction, F(00l). The results indicate that F(00l) increases from 0.13 to 0.16. From electrical resistivity measurements as a function of temperature, we were able to separate contributions arising from both the grain misalignment and microstructural defects. We found appreciable degradation in the normal-state transport properties of samples with an increase in uniaxial compacting pressure. It seems that this type of behavior is associated with an increase in the influence of microstructural defects at the intergranular level. The experimental results are analyzed in the framework of a current conduction model of granular samples. (AU)

• FAPESP's process: 05/53241-9 - Study of intergranular phenomena in ceramic materials
• Grantee: Reginaldo Muccillo
• Support Opportunities: Research Projects - Thematic Grants