We have measured the upper critical field of (La.925Ba.075)2CuO4-y in the range from 0 to 30 Tesla in the hybrid magnet at the Francis Bitter National Magnet Lab. The resistive transition in zero field onsets above 3 OK, with .9Rn at 29K, .1Rn at 27K and 0 below 24K (Rn = R(3 4K). Following the II-T curves for different fractions of Rn we find substantial differences in the temperature dependence of the apparent critical field. However, for (H,T)=.9Rn there is good agreement with simple pairbreaking behavior with an extrapolated Hc2(0) of 46 Tesla. At 4K there is no measurable resistance to 30 Tesla.
All Science Journal Classification (ASJC) codes
- 化學 (全部)