Angle dependence of magnetization in a single-domainYBa2Cu3Oxsphere

Abstract

The crystal angle dependence of magnetization has been measured in spherically shaped, single-domain ${\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{x}$ (YBCO). The single-domain sample is processed by a seeded-melt growth process in which a small ${\mathrm{NdBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{x}$ seed is used to induce domain growth through a peritectic reaction in YBCO. It has been found that the angle dependence of magnetization can be obtained in a series of zero-field-cooled hysteresis loop measurements with warm-ups well above ${T}_{c}$ between each measurement at a specific angle. In contrast to previously reported results, we have found that the angle dependence exhibits a sawtooth wave between 0\ifmmode^\circ\else\textdegree\fi{} and 360\ifmmode^\circ\else\textdegree\fi{} over a wide range of temperatures and fields. Furthermore, we have also measured the angle dependence on a YBCO plate and found similar behavior, indicating that the sawtooth wave is intrinsic to the superconductor. A physical model has been developed to explain the angle dependence of magnetization observed in this experiment.