Comment on “Angle dependence of magnetization in a single-domainYBa2Cu3Oxsphere”

Abstract

The model proposed by Tent et al. [Phys. Rev. B 58, 11 761 (1998)] to account for the angle dependence they observed in the magnetization $〈M〉$ of a single-domain sphere in a series of zero-field-cooled hysteresis loop measurements with warmups above ${T}_{c}$ between each measurement at a specific angle, is presented in a different perspective. Calculated curves of $〈M〉$ versus \ensuremath{\theta} which are symmetric with respect to $\ensuremath{\theta}=0\ifmmode^\circ\else\textdegree\fi{},$ 90\ifmmode^\circ\else\textdegree\fi{}, 180\ifmmode^\circ\else\textdegree\fi{}, etc., are shown to ensue from their model when the corrected formulas are exploited.