Phase separation in antiferromagnetic YBa 2 Cu 3 O \it 6+x

Abstract

We present a detailed study of the ZF‐μSR precession signals in AF YBa2Cu3O6+x for a series of 0.06\,\leq\,x\,\leq\,0.39 ceramic samples. Careful analysis of the temperature and oxygen content dependence shows a complex behaviour of the magnetic field at the muon site. The two main novelties are that a) the muon does not diffuse freely above 250 K, as previously stated, and that b) mobile holes phase separate, inducing a finite size reduction of the AF order parameter.