INVESTIGATION OF OXYGEN RADIATION-STIMULATED DIFFUSION IN YBA2CU3O7-XCERAMICS BY (N,ALPHA)-RADIOGRAPHY TECHNIQUE

A technique to determine the oxygen distribution in high T(c) supercon ducting YBa2Cu3O7-x ceramics has been developed based on the (n, alpha )-radiography method. The technique allows for the study of spatial ox ygen distribution in superconducting ceramics as well as monocrystal s amples without destruction of the sample, with spatial resolution not less than 1 mum and a relative standard deviation of 1.5%. By means of the technique elaborated on, the influence of the radiation-stimulate d diffusion of oxygen on the super-conducting phase formation in yttri um ceramics was studied. In the experiment the oxygen distribution in the samples with a narrow transition (DELTAT approximately 1 K) and a widened one (DELTAT approximately 10 K) were compared. The oxygen dist ribution radiograms for samples annealed under gamma-irradiation provi de strong evidence for the influence of the irradiation on crystalline ordering in the basis plane.