High performance batch production of LREBa2Cu3Oy using novel thin film Nd-123 seed

Abstract

A batch production for fabrication of LREBa2Cu3Oy (LRE: Sm, Gd, NEG) “LRE-123” pellets are developed in air and Ar-1% O2 using a novel thin film Nd-123 seeds grown on MgO crystals. The SEM and XRD results conformed that the quality and orientation of the seed crystals are excellent. On the other hand, new seeds can withstand temperatures >1100°C, as a result, the cold seeding process was applied even to grow Sm-123 material in Air. The trapped field observed in the best 45mm single-grain puck of Gd-123 was in the range of 1.35T and 0.35T at 77.3K and 87.3K, respectively. The average trapped field at 77.3K in the 24mm diameter NEG-123 samples batch lies between 0.9 and 1T. The maximum trapped field of 1.2T was recorded at the sample surface. Further, the maximum trapped field of 0.23T at 77K was recorded in a sample with 16mm diameter of Sm-123 with 3mol% BaO2 addition. As a result we made more then 130 single grain pucks within a couple of months. Taking advantage of the single grain batch processed material, we constructed self-made chilled levitation disk, which was used on the open day of railway technical research Institute. More then 150 children stood on the levitation disk and revel the experience of levitation. The present results prove that a high-performance good-quality class of LREBa2Cu3Oy material can be made by using a novel thin film Nd-123 seeds.