Application of ESR to High-T_c Superconductors and Related Materials: I. ESR Study of Cu₂₊ as a Probe of Crystal Growth Rates of Y₂BaCuO_y at High Temperatures

Abstract

A number of pellets with nominal concentration ratio of Y:Ba:Cu =2:1:1 have been sintered in air at temperatures between 800°C and 1400°C for 1 min ~24 h. The heat-treated samples were quenched to room temperature and the crystal growth rates of Y 2 BaCuO y≃5 were measured using ESR of Cu 2+. Systematic data on the growth rates were taken as a function of heat-treatment temperature and period.