Microstructural and elastic behaviour of OCMG-processed NdBaCuO materials

Abstract

A systematic investigation of an HTSC material viz; Nd 1.8Ba 2.4Cu 3.4O y superconductor prepared by the oxygen controlled melt growth (OCMG) process has been undertaken by studying its microstructure and elastic behaviour. The results are compared with those obtained on samples prepared by melt powder melt growth (MPMG) processed YBa 2Cu 3O y material. The X-ray diffraction studies of the new material clearly indicate the predominant structure of NdBa 2Cu 3O y. The microstructural investigations performed by means of optical and scanning electron microscopy confirm the presence of a second phase formed due to the uniform distribution of Nd 4Ba 2Cu 2O 10 (Nd-422) particles of size 1–12 μm size in the Nd-123 matrix. Further, magnetization measurements also show that the sample exhibits a pronounced secondary peak effect along with a critical current density value of 36 000 A/cm 2 at T=77 K in a field of 1.6 T applied parallel to the c-axis. Finally, the ultrasonic velocity measurements reveal that the elastic anomalies generally observed among most of the RE-123 materials, especially in the temperature region of 100–250 K are totally absent in the case of Nd-123 of the present investigation.