Orientation of Y₂BaCuO₅ precipitates during unidirectional solidification of Y₁Ba₂Cu₃O_{7- delta} under a magnetic field

The effect of a vertical magnetic field on Y₂BaCuO₅ (211) precipitates during horizontal unidirectional solidification of YBaCuO has been investigated. EPR shows first that some of the residual 211 particles are not randomly oriented in the 123 matrix when the sample is processed under a magnetic field. Secondly, the analysis of the angular dependency of the EPR spectra shows that these particles tend to be oriented in the 123 crystal with their b₂₁₁ crystallographic axis parallel to the applied magnetic field and also to the C₁₂₃ axis. X-ray pole figures on the same sample lead to an identical conclusion. The consequences of this observation regarding Y₁Ba₂Cu₃O_{7- delta} (123) crystallization are discussed.