Uniaxial superconducting particle in intermediate magnetic fields

Abstract

The problem of an anisotropic uniaxial superconducting particle of a general ellipsoidal form in the magnetic field ${H}_{0}$ such that ${H}_{c1}\ensuremath{\ll}{H}_{0}\ensuremath{\ll}{H}_{c2}$, is considered. It is shown---in agreement with experimental data---that particles of high-${T}_{c}$ materials at $T<{T}_{c}$ must orient with their $c$ axis normal to the applied field. The torque acting on a particle is evaluated and shown to be independent of the ellipsoid shape. The torque is associated with the magnetization component perpendicular to the field direction.