CU-63 65/LA-139-NMR STUDY ON THE ANTIFERROMAGNETIC ORDERING IN LA-BASED HIGH-T-C CUPRATE LA2-XSRXCUO4 AROUND X-CONGRUENT-TO-0.115/

In order to investigate the origin of the anomalous dip in T-c at x co ngruent to 0.115 for La2-xSrxCuO4, the temperature dependence of Cu-63 /65/La-139-NMR spectra has been studied on samples prepared by the spr ay-dry method. Spectra of Cu-63/65-NMR for the sample x congruent to 0 .115 showed a huge broadening at 4.2 K, demonstrating the existence of the antiferromagnetic ordering of 3d-spins. The Neel temperature dete rmined by La-139-NMR, showed maximum of T-N congruent to 32 K at x=0.1 15, which just coincided with the location of the dip in T-c, suggesti ng the crucial interplay between the antiferromagnetism and the suppre ssion in T-c.