Nonlinear magnetic response of semiconducting Y 1Ba 2Cu 3O 6+ x

Abstract

We report the magnetization M as a function of magnetic field H at T=77 K for semiconducting Y 1Ba 2Cu 3O 6+ x with x<0.5. For x=0 and T=77 K, there is a superlinear dependence of M on H, suggestive of spin-flop of the canted component of Cu ++ on the CuO 2 plane at a critical field. A strong hysteresis effect has been observed in M( H), indicative of first order transition at a critical field for the x=0 compound. For Y 1Ba 2Cu 3O 6+ x samples of x=0.25 and 0.34, M is sublinear with H, in agreement with the presence of ferromagnetically ordered regions due to oxygen doping.